Jumat, 30 April 2010

My 2002 Buick 3800 Won't Start After Fueling

The 3800 engine is a 3.8 liter V-6 engine that began as a V-8 engine with two cylinders left off. It was first introduced in a Buick in 1962. Since then it has undergone two major updates, the second in 1995. It has become the mainstay of V-6 engines for cars throughout the General Motors line. All 2002 Buicks that were equipped with a V-6 used the 3800. Of the service bulletins issued by General Motors for 2002 Buicks with the 3800, only seven relate to fuel issues and none involves problems with restarting after fueling. Motorists occasionally have problems starting a car after refueling, but it usually has nothing to do with the type of car or engine.

Instructions

    1

    Remove the gas cap, then try starting the car again. If the fuel tank gets too full it can create a vacuum that prevents gas from reaching the engine. The purge valve in the fuel tank normally prevents this. After the engine has started, put the gas cap back on. This problem will not affect drivability or cause any other problems. Mention it on your next routine service visit.

    2

    Wait at least five minutes and then try again. As cars age, some develop a problem starting when the engine is hot. Try starting every five minutes. Do not crank too frequently or you could overheat the starter. If this resolves the problem, schedule a service appointment, as it could indicate a more serious underlying problem.

    3

    Have a mechanic check for tainted fuel. If the fuel you used has been contaminated either your car will not start at all or will run very roughly after starting. You will need to get the car to a repair shop right away to have the fuel tank and lines purged and cleaned by a professional mechanic.

    4

    Have the car towed to a repair shop if no simple solution works. Sometimes a problem builds over time and may just coincidentally exhibit symptoms after fueling. For example, systems that control the fuel to air ratio could be deteriorating in a way that does not yet affect cold starts, in which the oxygen is dense, but does inhibit hot starts, in which the oxygen content is thinner. If the problem has occurred several times, you should schedule an appointment at an auto repair shop. Recurring symptoms are indicators of a problem which you want to have corrected.

The 1985 Chevrolet S10 2.8 Engine Turns But Won't Crank

The 1985 Chevrolet S10 2.8 Engine Turns But Won't Crank

If the engine in your Chevrolet S10 can be turned manually this indicates that it is not locked up internally. This failure to crank can be attributed to either a weak or damaged starting system, or a fault in the ignition switch. The majority of starting problems in all vehicles are directly related to a weak or discharged battery. If the battery is weak, you should charge it properly before proceeding to troubleshoot any of the vehicle's other components.

Instructions

    1

    Raise the hood of your S10 and locate the battery. Inspect the cable clamps. If the clamps are corroded, remove the negative clamp by turning the bolt counter-clockwise with the wrench. Clean the clamp and the terminal with the battery brush. Leave the negative clamp off and repeat with the positive clamp. Replace the negative clamp first and then replace the positive clamp by turning the bolts clockwise.

    2

    Inspect all wires and cables leading to the battery. If any components are loose or damaged, repair or replace them.

    3

    Place the ignition in the "on" position and determine if the headlights and wipers work. If they do not work, the problem is likely a bad ignition switch. If they do work, the problem is likely related to the starter itself.

    4

    Remove the battery cable clamps by turning the bolts counter-clockwise. Remove the negative clamp first. Remove the starter by turning the mounting bolts counter-clockwise with the socket set. Have the starter tested for proper operation. Most auto-parts stores will have the equipment to test starters.

Kamis, 29 April 2010

Signs of a Bad Electrical System in a Car

Signs of a Bad Electrical System in a Car

Electrical problems may seems intractable and confusing, but they're actually fairly easy to diagnose once you know the basics. An electrical system can only fail in so many different ways; once you figure out what kind of failure you're dealing with, finding the source is just a matter of time and persistence. Just remember that electrical systems aren't week-old hot dogs. They don't "go bad," they just malfunction in one place or another.

Blowing Fuses

    Electrical system problems will often initially manifest as blown fuses. Fuses are the weak link in your electrical system, designed to overheat and fail before any of the accompanying wires do. If the bare metal under the insulation of a positive wire touches the frame or touches the bare metal core of a ground wire, the heat created during that brief contact will effectively weld the two together. The result is an overload in the circuit and blown fuses. Bear in mind, though, that frozen or malfunctioning electric motors can also cause blown fuses.

Weird Crossovers

    The average electrical system is a study in engineering convenience on the part of manufacturers. A car maker will often connect completely unrelated systems through the same electrical circuit; radios run through the dome light, transmission controllers run through the gauges and engine controls share a circuit with that electric flashing skull shifter knob. If activating your windshield wipers turns your radio off or rolling up the windows kills your engine, then odds are that you have an unintended crossover or short within a single system.

Random Accessory Shut-Off

    Resistance in a circuit causes electrical energy to get stuck at the point of resistance. Since the energy can't go forward and more energy keeps piling up behind it, the electrical energy begins to "vibrate" and create heat. Since a given conductor can only move a certain amount of energy, any heat in the line will create a cascade effect of heat buildup. Eventually, the heat will get high enough that the circuit will blow a fuse or fail to transfer power to the accessory.

Battery Death and Amp Draw

    If you park your car at night and constantly find that the battery has died by morning, then odds are that you're experiencing some kind of short or amp draw (accessory not turning off). To test for a short in the system, remove both battery cables and connect a digital multimeter (set to ohms of resistance) and touch the probes to your cable terminals. It should read somewhere around 100 ohms; if it reads zero ohms, then you have a dead short in the system. To test for amp draw, disconnect the positive terminal, set your DMM to read in the 10-amp range and touch the probes to the positive battery terminal and battery cable terminal. You should get a reading in the milliamp (0.001-amp to 0.009-amp) range. Any higher than that and something isn't turning off.

How to Troubleshoot Clicking in a Car's Power Window

How to Troubleshoot Clicking in a Car's Power Window

Power windows in cars should roll up and down freely and quietly with the flip of the switch in either direction. Some causes of clicking related to rolling the power window up and down can be repaired by the car owner. More complex problems require the attention of an automotive glass specialist and should not be attempted by the car owner in order to avoid damage to the electrical components of the power window mechanism.

Instructions

    1

    Roll the power window completely down.

    2

    Spray some WD-40 along the inside track of the window. This helps to prevent the window from sticking and clicking in dry or humid weather.

    3

    Roll the window up and down twice. The window should roll freely without clicking and sticking.

    4

    Evaluate the source of the click each time you use the power window switches. If the click is coming from under the dash then replace the appropriate fuse in the fuse panel of the car. If the click is coming from the power door switch itself, take the car in to the shop for a repair. Replacing the switch is a complex issue that shouldn't be rectified by the auto owner.

Rabu, 28 April 2010

My Transmission Is Not Going Into Third

Modern automatic transmissions have three basic systems: the mechanical system that transfers power from the engine to the driveshaft; the hydraulic system that controls the mechanical system's clutches and movement; and the electronic system that augments and controls the hydraulic system. A failure in any one of these can cause your transmission to refuse to shift or shift incorrectly. It all starts with understanding how an automatic transmission works.

Automatic Transmissions 101

    An automatic transmission uses a planetary gearset that utilizes a medium-sized, central "sun" gear, three to five small "planetary" gears that rotate around the sun gear and a large ring gear that encircles the planetary gears. The transmission use several toothed clutch packs, which are locked to the drum that contains the clutch pack, that sandwich between metal friction discs, which are locked to the shaft in the center. When the clutch pack receives pressure from the hydraulic system, the clutch discs squeeze down on the friction discs and lock the outer power-input drum to an inner shaft, which then sends that power to either the sun, planetary or ring gears.

Planetary Gear Function

    In first gear, the small planetary gears lock to the power-input shaft and the ring gear locks to the output. In second gear, the sun gear locks to the power-input, the planetary gear remains stationary and the ring gear gets locked to the output. Third gear is usually direct-drive, so the sun gear, planetary and ring gear are locked to both the power-input and output shaft. In overdrive, the ring gear gets the power, the planetaries remain stationary and the sun gear acts as the output.

Direct Drive Malfunction

    Third gear requires all of the transmission's clutch packs to engage at the same time, and as such requires more hydraulic pressure to engage. Thus, third gear will usually be the first one to go if your hydraulic system pressure is low because of clogged passages, a low fluid level, a clogged transmission fluid filter or a malfunctioning oil pump. Slipping clutches (or the ring-gear's outer band) can also cause a third gear malfunction, though these will generally manifest in other gears as well.

Other Possibilities

    Many modern cars have a "limp home" mode programmed into the engine/transmission control computer that will de-tune the engine and keep the car in a lower gear if something goes wrong with the engine. This will always trigger a check engine light, and will generally be accompanied by a noticeable drop in engine power. A faulty vehicle speed sensor may also keep the transmission out of third, as may any number of electronic/hydraulic solenoids and actuators. Which sensors, solenoids or actuators might be responsible can vary greatly by transmission design and model year. If changing the fluid and filter doesn't work and a code-reader doesn't reveal the problem, then odds are you'll need to take your transmission to a shop to diagnose the problem.

Word of Warning

    Do not ever, ever let anyone talk you into flushing your transmission fluid if the existing fluid has more than two years or 20,000 miles on it, whichever comes first. The chemical components in transmission fluid break down over time, causing the fluid to change in viscosity and thermal properties. This fluid impregnates into the clutch pack, and is chemically different enough from brand new fluid that the two may prove completely incompatible. The end result is that the clutches slip, fail to grip the friction discs and fry. You'd be far better off simply draining the oil pan and replacing the fluid every 10,000 miles, then flushing after 30,000 miles. This will give the new fluid time to impregnate into the clutch packs and prevent premature failure.

How to Troubleshoot Oil in My Radiator

How to Troubleshoot Oil in My Radiator

Antifreeze---or coolant---engine oil and transmission fluid all have their specific tasks of providing lubrication or providing pressure to activate a pump. Each fluid has a separate container or sump that has seals to keep the fluid from escaping. When one fluid enters another fluid's sump or containment area, problems with contamination will result. Oil that appears in the radiator can be a serious problem, because the oil robs the coolant of its ability to dissipate heat. Oil in the radiator can foam up and cause air pockets that cause the water pump or thermostat to malfunction. A vehicle owner needs to know how the oil entered the radiator and the proper procedure to repair it.

Instructions

    1

    Determine if you have oil in the radiator by removing the radiator cap and examining the condition of the coolant. Do this with the engine running just after startup. Check the overflow reservoir if there is radiator cap, which is a sealed system. Oil in the water will appear a muddy brown, frequently "frothed" up to the consistency of a milkshake.

    Drive the vehicle for an extended period of time, enough to raise the engine temperature to its normal operating limit. Park the vehicle and read the temperature gauge. If the indicator needle points to above-normal temperature limits, and your inspection of the coolant revealed muddy brown contamination, you will have to check the engine.

    2

    Place the vehicle in park or neutral with the emergency brake set. Use a spark-plug socket and wrench to remove the spark plugs from the vehicle. Screw in the compression tester, or use hand pressure for the push-type, into the spark plug hole. Remove the high-tension coil or coil pack wire. Have an assistant turn the engine over with the ignition key seven or eight times and stop. Read the pounds per square inch (psi) on the gauge. Read each cylinder and record the numbers. Note any deviation in the readings. Any cylinder that reads 30 pounds or lower will have a problem. This could point to a blown head gasket.

    3

    Hook up a vacuum gauge to a vacuum source on the engine. The best sources will be a hose coming from the intake manifold, carburetor or throttle body. With the engine idling, read the gauge and record the number. Refer to your owner's manual for the correct vacuum reading, which reads in inches of mercury. Any number lower than the manufacturer's specification will indicate excessive vacuum entering the combustion chamber caused by a warped or cracked cylinder head or defective head gasket.

    4

    Turn the engine off and check the oil dip stick. Any light brown coloring or foamy substance on the tip indicates that a cylinder passage in the head or block that has crossed an oil passage with a water passage. The probable cause will be a blown head gasket, cracked or warped head.

    5

    Hook up a radiator pressure tester to the radiator cap inlet. Manually pump the tester up to the prescribed pressure that reads on the top of the radiator cap. You can exceed the pressure by a few pounds without damaging the system. Wait for about five minutes and see if the pressure drops slowly. Listen for any hissing sounds coming from the location of the cylinder head. Such symptoms will indicate a defective gasket seal, and possibly an exterior crack, in the head.

How to Tell That Your Front Struts Need Changing on a Honda Civic

How to Tell That Your Front Struts Need Changing on a Honda Civic

The Honda Civic is a popular car thanks to its reliability, build quality and frugal gas consumption. Most Civics also happen to be fun cars to drive. The front struts on a Civic are critical to its handling. Over time, struts begin to wear, resulting in a softer ride, poor handling and a noisy and compromised suspension. It is relatively easy to determine whether your Civics struts are still in good, usable shape.

Instructions

    1

    Drive the car over a bumpy road and see how it handles. The front struts should provide a relatively smooth ride, even over rough sections of road. If the struts bounce up and down, make crashing and banging sounds, and the steering feels loose, the struts are likely bad.

    2

    Perform a series of cornering maneuvers in your Honda at a spirited pace to see how the car handles. When you turn the steering wheel into a corner, the front end should respond relatively quickly, and the handling should feel stable and predictable. If the car leans excessively and feels loose rather than stable and safe, the struts are likely past their usable life.

    3

    Test the stiffness and behavior of the struts by pressing down on the corners of the car. Stand near one corner and press on the fender just above the wheel with your hands. If the struts are in good shape, they should be relatively difficult to press down on. When you press the corner of the car down, the strut should compress and then rise back up quickly and smoothly, coming to a stop without excessive bouncing. If the strut rises slowly, is easy to bounce up and down and does not come to a smooth stop after pressing the corner of the car down, the struts are probably worn. Test both sides of the car.

    4

    Inspect the struts for damage. Loosen the lug nuts that hold the front wheels to the car. Lift the vehicle with a floor jack and lower it onto jack stands. Inspect the body of the strut, from the top to the bottom. A strut that is in good shape will not be leaking any fluid from the strut housing. But if the strut is blown out from excessive use, it may be leaking fluid onto the body of the strut.

How to Troubleshoot the AC in a 1990 Buick Century

If you're having trouble with the air conditioning in your 1990 Buick Century, you should troubleshoot to identify the problem. Common problems that affect the performance of an air conditioner include damaged hoses, a clogged condenser and loose or damaged belts. Once you identify the problem, you can make the necessary repairs or take the car to the automotive shop.

Instructions

    1

    Check the compressor drive belt carefully for wear or deterioration. If the belt or worn or damaged, replace it.

    2

    Check the tension on the belts with a ruler and a straight edge. Place the straight edge across two of the pulleys that are 7 to 12-inches apart; there shouldn't be more than a -inch of deflection. If the pulleys are up to 16-inches apart, there shouldn't be more than -inch of deflection. If there is too much deflection, the belt tensioner may require replacement.

    3

    Check the system hoses. Look for hard spots, cracks or deterioration and wear. Check the hoses, especially around the fittings, for any oil bubbles, seepage or evidence of leakage. Replace the hoses if necessary.

    4

    Inspect the fins on the condenser for debris. The condenser is considered a radiator for the air conditioning unit and is mounted in front of the radiator. Use compressed air to clean the debris out of the condenser.

    5

    Test for the correct refrigerant level. This can be accomplished by warming the engine up to a normal operating temperature and placing the air conditioning temperature selector on the coolest setting. Ensure the the blower is at the highest setting and open the doors of the vehicle. When the compressor engages, feel the inlet and outlet pipes on the compressor -- one side should feel colder than the other. If the refrigerant looks foamy, it is low.

How to Find an Oil Leak on a 1994 GMC Truck

How to Find an Oil Leak on a 1994 GMC Truck

The 1994 GMC models include several engine sizes, based on whether the model is a Sierra or a Jimmy. Finding where oil is leaking is a similar process among all the engine types. The size of the engine and the location of cooling system parts are the main variables. Oil leaks from a vehicle can cause ugly spots in a driveway or parking lot, as well as contaminate ground water sources. One quart of motor oil can contaminate as much as a million gallons of water. The economic effect of having an oil leak is substantial as well, as there is a cost involved in having to perpetually replace lost oil.

Instructions

    1

    Open the hood of the GMC truck. Visually inspect the upper engine area and the upper sides of the engine for any sign of grit buildup or oil sediment. Leaking or seeping oil will attract dirt and debris and create a form of sludge around the leak. Parts of the upper engine to inspect are the valve cover gaskets, the lower intake manifold area and the upper portion of the sides of the engine. If an oil leak is visible, write down its location and the associated part.

    2

    Lift the front of the truck, using a 2-ton or greater capacity jack. Set jack stands beneath both front lower control arms. Using vehicle lift ramps in this step will eliminate the need for a jack or stands.

    3

    Put on a pair of safety glasses or goggles. Lie under the front of the truck and slide your body so that you can visually inspect the lower engine area. There are several areas for potential oil leaks beneath the vehicle, due to greater exposure to the elements as well as the increased oil pressure in the crankcase.

    4

    Inspect the front of the engine first. Look around the large pulley, known as the crank pulley. This pulley is linked directly to the GMC's oil system parts, and the seal on the crank or in the front of the oil pan can rupture over time. Look for any sign of excess moisture around the bottom front area of the engine. Note any leak you find and the part associated with it.

    5

    Slide farther back under the belly or middle of the engine to inspect the bottom-most parts of the engine, as well as the bottom sides. Focus mainly on the oil pan gasket and the oil filter gasket. Inspect the oil pan gasket. Find and inspect the oil filter area. If you notice excess moisture around either of these areas, note it. Look on the bottom sides of the engine above the oil pan for signs of leaking oil. A cracked engine head can seep oil or coolant, depending upon where it is cracked. Note any signs of leaking from the lower sides of the engine. Follow the moisture to it's source if possible and note any parts that may be related to the leak.

    6

    Slide to the rear of the engine. There is a main seal between the transmission and the engine. The seal can rupture over time, due to torque on the seal and debris being pushed out of the engine through the seal. Note any moisture on the rear of the engine, between the engine and transmission, as this may be a sign of a blown rear main seal.

    7

    Remove yourself from the bottom of the vehicle and go over your notes as to where you have seen excess moisture and possible oil leaks. If you notice only a minor oil leak, you can add an engine sealer as a temporary fix. But any parts related to leaks, such as gaskets and seals, will eventually have to be replaced.

Senin, 26 April 2010

What Causes Boost Spikes?

A common problem with turbocharged engines is a sudden spike in boost pressure when the turbo initially spools. This is known as boost spike. Some boost spiking should be expected with every turbo application due to the turbo pressure equalizing under sudden acceleration. However, excessive boost spike, which is most common on modified turbo engines, can damage the turbocharger and other engine components. For this reason, boost spike should be diagnosed as soon as possible.

Damaged Turbocharger

    A damaged turbocharger unit is one cause to boost spikes. If the turbo shaft or bearings are worn, the turbo wheel will spool inconsistently. This can cause sudden boost spikes, as well as an inconsistent peak boost pressure. Another issue that causes boost spikes is a malfunctioning turbo wastegate. The wastegate allows excess exhaust gas to bypass the turbocharger under acceleration. If the wastegate spring or actuator malfunctions, it may allow for inconsistent exhaust flow into the turbocharger. This will cause boost spikes and/or low peak boost pressure.

Intercooler Piping Leak

    The pressurized air from the turbocharger is circulated through the intercooler system and piping before it enters the engine. A loose intercooler pipe or other leak will allow a substantial amount of boost pressure to escape the system. Since the turbo pressure is constantly monitored, the turbocharger will try to compensate for this leak by producing increased boost pressure. The inconsistency in boost pressure inherent when a boost leak is present will cause the boost pressure to spike and hold inconsistently.

Boost or Vacuum Leak

    Just as with an intercooler leak, a boost or vacuum leak in any other part of the turbocharger system will cause boost leaks to occur. The turbo system features various vacuum lines connected throughout various components in order to monitor and equalize boost pressure. If these lines are damaged or detached, boost leaks and spiking will occur. Boost leaks at other locations will likewise lead to boost spikes. Common places for boost leaks to develop are any components that feature rubber gaskets or fittings, such as the engine throttle body and intake manifold.

Other Causes

    On the upper intercooler pipe is a blow-off valve, which releases excess boost pressure from the turbo system when the engine throttle is lifted. Blow-off valves feature an actuator so that the unit opens and closes properly under boost pressure. If this actuator is damaged or improperly set, boost leaks and boost spikes may occur. If you have an aftermarket boost controller installed on your system, it may be the source of boost spiking. An improperly installed or leaking boost controller will lead to boost spikes.

How to Reset the Code on a 2002 Ford Focus

How to Reset the Code on a 2002 Ford Focus

Your 2002 Ford Focus's "check engine" light will stay on if you do not reset the trouble codes that caused the light to come on, even if you or your mechanic carried out the needed repair. Thankfully, clearing the codes and turning off the instrument panel warning light is relatively simply. All you need is an onboard dagnostic code scanner (an OBD II scanner). It can be the same one you used to retrieve the codes that led to the recent repairs. As a task, it will take less than five minutes.

Instructions

    1

    Feel around the area beneath the Ford's dashboard and steering column. You will find a diagnostic input jack there.

    2

    Connect your diagnostic scanner to this jack. Some scanners will immediately turn themselves on if they sense a connection with the Ford Focus's diagnostic computer.

    3

    Turn the Ford Focus on. Try the electrical system first, and if a connection doesn't result, double check the scanner's connection to the diagnostic jack. As soon as a connection is realized, the Ford's trouble codes will appear on the scanner.

    4

    Triple-check to ensure that no new codes have appeared on the scanner. Once you are certain, press the "clear" button on the scanner. This will turn your "check engine" light off.

Minggu, 25 April 2010

Why Is a Nissan Sentra Overheating?

Nissan Sentras have been known to overheat due to collapsed radiator hoses, plugged up catalytic converters, and clogged cooling tubes in the radiator. There have even been Sentra recalls related to overheating crankshaft position sensors.

Low Fluid

    The most common cause of overheating is a lack of engine coolant. Check your fluid levels. There are hot and cold marks on the coolant reservoir. If fluid isn't between the lines, even though you recently filled it, a coolant leak could be the culprit.

Electrical Causes

    The engine cooling fan helps move air through the radiator when you're not going fast enough for air to be forced through naturally. The fan turns on when your engine thermostat shows operating temperature has been reached. If either your thermostat or fan is broken, it can cause your engine to overheat.

Sentra Recall

    2002 and 2005-2006 Sentras equipped with 2.5-liter engines were recalled due to the crankshaft position sensor overheating. This causes an interruption in the sensor's signal which can cause the engine to cut off with no warning. If you suspect your overheating is stemming from this known Sentra problem, take your car to a Nissan dealer to see if you are covered under the recall.

What Happens If Your CV Joint Breaks?

What Happens If Your CV Joint Breaks?

Constant-velocity (CV) joints sit on either end of the drive shaft on front-wheel drive cars. They allow for up and down motion and bend in any direction when steering.

Causes

    Because CV joints are always in motion when the car is moving, they are susceptible to damage. The joint is covered with rubber that deteriorates with age. Sometimes if the car hits a bump suddenly or is in an accident, the joint can break suddenly.

Significance

    If the CV joint breaks, the car will not be able to run. The CV joint transfers torque from the drive shaft to the wheels, necessary for motion.

Signs

    You can tell a CV joint is damaged because the car will make a clicking or popping noise coming from the vicinity of the wheels. The noise will be louder or more obvious when making sharp turns.

My 1990 Volvo Won't Start After Turning It Off

My 1990 Volvo Won't Start After Turning It Off

As the old saying goes, if your car won't start, you've either got no fuel or no spark. While this is an oversimplification, it does provide a good starting point for determining why your 1990 Volvo 240, 740, 760 or 780 won't start after it is turned off. If the Volvo is missing an electrical charge from the battery, proper fuel and air mixture, spark, proper timing or proper compression, the car won't start up. A handful of recalls and other issues for the 1990 model year involved the fuel delivery system, fuel tank and electrical system and may be the contributing to the issue.

Instructions

    1

    Ensure that your Volvo is in the P or Park position, if it is an automatic transmission. If necessary, place it in park and try starting the car again. An automatic transmission is standard on the 1990 Volvo 760 and 780 and available as an option on the 240 and 740.

    2

    Ensure that the clutch pedal on your Volvo is fully depressed when starting, if it is a manual transmission. Press the clutch pedal all the way to the floor and hold it there while trying to start the car again.

    3

    Determine if the engine is cranking at normal speed when you turn the ignition key. If the engine makes a growling noise and sounds as though it is going to start when you turn the key, the engine is cranking normally. Ensure that you have enough fuel in the tank. Though there were no recalls involving the fuel gauge for 1990 Volvos, keep in mind that the fuel gauge may be stuck or broken. If you have fuel in the tank, take your Volvo to a technician. The fuel might not be making it into the engine due to a bad fuel pump or clogged fuel filter. Volvo models in 1990 and earlier often have problems with the fuel pump relay, especially right after the engine has been turned off. Wait an hour or so and attempt to start it again, then have a Volvo technician replace the relay. Also, the ignition system may have a problem, such as the coil or distributor cap, or the timing belt or compression may be off.

    4

    Determine if the engine is cranking at a slow speed when you turn the ignition key. If you hear the growling noise but it is slow, with a second or so between cranks, the engine is cranking slowly. The battery may have a low charge. Try turning on the windshield wipers with the ignition key in the "On" position. If the wipers move but at a slower rate than normal, the battery may be low. You can try jumpstarting the car using jumper cables or taking the battery into an auto parts store that can recharge the battery. If the battery is not low on power, take your Volvo to a technician. The starter motor may be going bad or you could have internal engine problems.

    5

    Determine if the engine does not crank but only makes a clicking sound when you turn the ignition key. If you hear a clicking sound, the battery may have a low charge. Turn on the windshield wipers with the ignition key in the "On" position. If the wipers move but at a slow rate, the battery may be low. Try jumpstarting the car using jumper cables or taking the battery into an auto parts store that can recharge the battery. If the battery is not low on power, take your Volvo to a technician. The starter motor or a part of the starter system may have failed. Also, a number of conditions may have caused your Volvo to enter a "no start" state, such as the SRS airbag sensor light turning on or a faulty RPM sensor.

    6

    Determine if the engine does nothing at all when you turn the ignition key. Turn on the radio or the lights. If they don't turn on, the battery may be at fault. You can try jumpstarting the car using jumper cables or recharging the battery at a qualified auto parts store. If the battery is OK, you should take your Volvo to a technician. The ignition switch, starter electrical system or starter motor may have failed.

Sabtu, 24 April 2010

How to Tell If You Have Water in Your Gas

How to Tell If You Have Water in Your Gas

A tank full of bad gasoline in your vehicle can cause a variety of problems, including lasting damage to the engine. It is important to know the symptoms of bad gasoline because the sooner you can determine that your vehicle has bad gas, the quicker you can correct the problem. Bad gasoline typically is caused by water mixing with the fuel. To fix the issue, add a fuel treatment to the tank or manually extract the bad fuel before the engine can use it.

Instructions

    1

    Determine when you last put fuel in your vehicle. Gasoline that contains a high concentration of ethanol does not have a very long shelf life and experiences what is called "phase separation" in as little as 30 days. Phase separation occurs when the ethanol and the water in the fuel bond together and separate from the gasoline. If the gasoline in your tank is more than a month old, you should assume that it is no longer good and probably needs to be drained from your vehicle's tank by a mechanic.

    2

    Start the car. Pay attention to whether it starts properly, or if it is either struggling to start or starts and then stalls. If it has a hard time getting and staying started, and the only thing that has changed is that you just put gasoline in it, you might have watered-down fuel.

    3

    Let your car sit and idle. Pay attention to whether it idles evenly and consistently, or if it sputters, surges or stalls out. These can all be symptoms of bad gasoline.

    4

    Drive the car. Pay attention to how it responds when you press the accelerator. Hesitation, sputtering, coughing or loss of power are signs your vehicle might have bad fuel.

    5

    Look at your gas gauge. If you only have a little bit of fuel and suspect it is bad, fill the tank up with a high octane (premium) fuel, then add a fuel treatment product to take care of the problem. If your vehicle has a full tank of gasoline, call your mechanic and get advice about how to handle the situation. You might need to have the bad gas siphoned out and replaced with premium gas.

The Signs of Leaking Around an AC Compressor

The air conditioning (AC) compressor in your vehicle provides cool air and power for the air-conditioning system. This small device works by building up pressure as the engine runs and propelling cold air into your car. The AC compressor only contains a small amount of fluid, which acts a lubricant to keep its parts cool and running smoothly during operation. If the fluid leaks out of the AC compressor, you must repair your vehicle's air conditioner.

Noises

    If the fluid leaks out of your vehicle's AC compressor, you may hear noises and rattling as the compressor runs dry and lacks the lubrication it needs to run smoothly. Some compressors make more noise than others, but pay close attention if your vehicle's air-conditioning system begins making knocking noises or metallic or grinding noises, as these can indicate low coolant and/or a compressor that is about to stop functioning.

Seized Compressor

    Both oil and coolant circulate through the AC compressor, so if the fluids leak out, the compressor may seize up and stop working completely. If the compressor seizes up, the air conditioner will no longer cool the car, and you may hear squealing noises from the belts as they attempt to turn the seized-up compressor.

Visible Leaks

    Leaks can occur both externally and internally around your AC compressor. External leaks commonly occur around the compressor shaft seal, hoses, O-rings, gaskets, condenser, connectors or evaporator. Examine all these areas thoroughly if you believe your AC compressor is losing fluids. Visible leaks can be hard to detect, so you may need to use a dye or an electronic leak detector to pinpoint the leak's location. You may not be able to detect internal compressor leaks without taking the compressor apart physically.

1997 Ford Diesel Won't Start

1997 Ford Diesel Won't Start

The F-150 is popular in the U.S., often accounting for a large percentage of Ford's annual revenue. While the F-150 is often praised for its durability, it is susceptible to wear and tear that can lead to malfunctions, even when it comes to starting up the engine. Troubleshooting the ignition and fuel delivery systems are the first steps to take when determining why the F-150 won't start.

Instructions

If the F-150 Won't Crank

    1

    Procure another vehicle that has a battery with comparable voltage and perform a jump start on the F-150.

    2

    If the jump start is successful, idle the engine for a few moments to give the battery an opportunity to collect a charge.

    3

    After shutting down the F-150 and disconnecting the jumper cables, try to start it again. Failure to start at this point is usually indicative of a faulty battery, which will need to be replaced.

If the F-150 Is Cranking

    4

    Verify that there is fuel in the F-150's gas tank. If the fuel gauge reads empty but there is fuel in the tank, then the gauge will need to be replaced. Also ensure that the fuel contained in the tank is diesel fuel.

    5

    Using the spark tester, verify that each plug is giving adequate spark and is free of corrosion, which can impede the electrical connection.

    6

    Inspect the timing belt by removing the timing belt cover. If the belt has snapped or slipped from its position, seeking the services of a qualified automotive professional to replace/rehouse the belt is strongly recommended, as this is a highly complicated process that involves removing most of the front engine components.

What Are the Causes of an Intake Manifold Gasket Leak?

What Are the Causes of an Intake Manifold Gasket Leak?

The intake manifold gasket is designed to seal the gap between the intake manifold and cylinder heads. When the intake manifold gasket is damaged, it can begin to leak and can cause a variety of problems for your vehicle. If the intake manifold gasket develops a leak, it can cause coolant to enter the engine and may cause permanent damage to the engine.

Heat

    One of the primary causes of intake manifold gasket failure is heat. If your vehicle's engine overheats, the aluminum cylinder heads have a tendency to expand. As the metal expands, the gasket is crushed and will no longer provide an adequate seal. If your vehicle has seriously overheated, continues to overheat regularly or the coolant levels keep going down and you cannot find the leak, you should check the engine oil to make sure that you do not have coolant leaking into the engine oil.

Age

    Intake manifold gaskets are not designed to last forever. If your vehicle has high mileage or is older, it is possible that the intake manifold gasket has simply worn out from years of use and exposure to engine fluids. Some engines are more prone to intake manifold gasket failure due to their design or poor quality OEM gaskets. Plastic intake manifold gaskets are especially prone to failing over time.

Vacuum Leaks

    Vacuum leaks that are caused by a malfunctioning intake manifold gasket are less common than coolant leaks. However, it is possible for the intake manifold gasket to suffer damage, resulting in too much or too little air entering the intake manifold and mixing with the fuel. The vehicle will run poorly as a result.

How to Tell if You Have Vacuum Leaks in a D16Z6 Turbo

With 125 horsepower in stock form, the D16Z6 leaves something to be desired in performance when compared to some of the high-revving Honda B-series engines. But with the addition of a custom turbo system, the D16Z6 is able to churn out horsepower and torque figures up to and beyond its more powerful VTEC brethren. However, seemingly minor issues such as vacuum leaks can ruin the performance and reliability of the turbocharger and other components, diminishing horsepower output in the process. You should periodically check the turbo system for leaks to diagnose them before more complicated issues arise.

Instructions

Engine Tests

    1

    Start the engine and allow it to warm up to normal operating temperature. Have a passenger ride with you to safely observe the boost gauge while the engine is accelerating.

    2

    Observe the boost gauge at idle. The gauge should read a steady vacuum pressure as long as the engine rpm remains the same. Constant fluctuations in the vacuum pressure indicate a vacuum leak somewhere in the intake track.

    3

    Rev the engine at idle while observing the boost gauge. This will cause the gauge needle to quickly rise toward positive boost pressure. After you rev the engine, allow it to fall back to idle. The boost gauge should again read a steady vacuum pressure once you've lifted off the throttle. If the vacuum pressure fluctuates back and forth after revving, this indicates there is a vacuum leak.

    4

    Drive to a location where it is safe and legal to accelerate the engine to its rpm redline. Accelerate to redline while your passenger notes the behavior of the boost gauge. If there are no vacuum leaks, the boost pressure should quickly rise to maximum pressure in the mid-rpm range, then slowly taper off until redline.

    5

    Repeat the test multiple times to get a thorough observation of the turbocharger's behavior. Vacuum leaks will cause the boost pressure to fluctuate as the engine is accelerated. A leak also makes it harder for the turbocharger to maintain pressurization, so the max boost pressure will be lower than what it should otherwise be with your setup. Alternatively, a malfunctioning wastegate can also cause the boost pressure to fluctuate and/or remain beneath the max pressure setting.

    6

    Closely observe the acceleration characteristics of the engine. Boost leaks can cause the turbocharger and/or engine to feel hesitant because of inconsistent pressurization. Leaks can also throw off the engine's air-to-fuel ratio, which can make the engine feel rough under acceleration while also reducing power output.

Inspection

    7

    Ensure the engine has fully cooled down before you begin inspection; the turbo components become extremely hot under normal operation. Disconnect the intercooler piping from the throttle body. Use a spare rag or something similar to plug the outlet of the intercooler pipe.

    8

    Disconnect the air filter from the turbocharger intake. Use a smoke-generator machine to fill the intake track with smoke. Carefully examine the intercooler system and piping for signs of escaping smoke. This way, even pinhole leaks will be evident. Pay especially close attention to the locations where two sections of piping meet, as these are the most likely locations for vacuum leaks.

    9

    Replace any seals or piping adapters that show signs of leaks. Reconnect the intercooler piping to the throttle body, then use a socket wrench to check the tightness of all hose clamps throughout the intercooler system. Because of the turbo's heat and pressure, the rubber adapters secured by the hose clamps are likely to stretch over time, allowing for vacuum leaks.

    10

    Inspect all of the vacuum lines routed between the engine, intercooler piping and intake manifold. Since they are made of rubber, the vacuum lines can develop heat cracks over time. Check that all of the vacuum lining is free of cracks and other damage. Also make sure each vacuum line is securely connected to its proper location by referring to the vacuum diagram for your turbo kit.

    11

    Check and replace the various other seals throughout the intake track if you are still experiencing vacuum leaks. Rubber gaskets sealing the blow-off valve or boost controller are common culprits, as are the throttle body O-rings. To double-check for leaks, you can use the smoke-generator machine to blow smoke on the exterior of the intercooler piping and other turbocharger components while the engine is running. If vacuum leaks persist, they will be evident by turbulence in the smoke at locations where air is escaping the system.

Signs of a Cracked Head Gasket

Signs of a Cracked Head Gasket

A head gasket is an important component in internal combustion engines by keeping the coolant and oil separate. According to Dennis Parks, author of "The Complete Guide to Auto Body Repair," a cracked head gasket can harm your vehicle and can be extremely expensive to replace. When the head gasket cracks, the vehicle will exhibit many telltale signs.

Contaminated Coolant

    Contaminated engine coolant and constant engine overheating can indicate a cracked head gasket. According to Michael E. Gray and Linda E. Gray, authors of "Auto Upkeep," when a head gasket cracks, its broken seal allows engine coolant to leak out, causing the vehicle to overheat frequently. In addition, upon inspecting the engine's coolant, you might find that it has turned a milky-brown color. Oil leakage into the coolant system causes this brown discoloration. If a vehicle has contaminated coolant, the coolant system will require flushing along with a head gasket replacement.

Tailpipe Water and Smoke

    Water dripping from the tailpipe of a vehicle can also indicate a cracked head gasket. The vehicle's constant overheating and coolant leaks can cause other components of the engine to malfunction. If allowed to persist, these problems can cause the tailpipe to rust eventually. You can test for leaks by revving the engine while holding a piece of cardboard beneath the tailpipe so you can see water droplets. Additionally, you might notice white smoke appearing from your tailpipe, write the Grays.

Loss of Power

    Sudden loss of engine power is a common sign of a cracked head gasket. According to Deanna Sclar, author of "Auto Repair for Dummies," when the head gasket cracks, it causes a loss of engine compression. When your engine loses compression, the engine must work harder to generate power. In addition, the vehicle might idle at a higher rpm than it did before, causing wear to the engine.

Jumat, 23 April 2010

Symptoms of Alternator Problems on a Lexus SC 400

Alternator problems are sometimes difficult to diagnose. Alternator failure can exhibit mild to severe symptoms that can be initially overlooked. If you suspect that your Lexus SC 400's alternator is experiencing problems or has failed, look for telltale signs of trouble. Alternators perform the same function in every type of car.

Dead Battery

    If your Lexus's alternator is failing, your car may have a dead battery. Your alternator's job is to charge the battery. If you have a bad alternator, your battery will continue to die, even if you replace it with a new one. The only way to stop this problem is to replace the alternator.

Dim Lights

    A dying alternator causes your headlights to be dimmer than normal. They will continue to dim and fade until the battery completely runs out of juice and stops powering the car altogether.

Loss of Accessories

    If your alternator is failing, you may notice a loss of power to your vehicle's accessories as you travel. Items like your GPS, radio and even your dashboard lights drain power from the battery. If you turn your accessories off and your car seems to have a little more juice, or the dashboard lights get brighter, the problem is most likely your alternator.

Troubleshooting the Blower Fan on a 2003 Rendezvous

The 2003 Buick Rendezvous was equipped with a 3.4-liter V-6 in both the CX 2WD and CX AWD models. The blower motor is controlled by either a manual dial on the heater control panel or an automatic speed controller in the digital control panel. The blower motor controls the volume of air movement in the Rendezvous cabin. Testing and replacing the blower motor requires removal of interior body panels, as well as electrical testing equipment.

Instructions

    1

    Sit in the Rendezvous driver's seat and turn the engine on. Set the fan speed selector to the lowest setting. Move the fan speed from the lowest to the highest setting, one step at a time. If the blower motor works on some but not all settings, the heater control panel or the blower motor control processor are faulty and need to be replaced. If the blower motor does not work at any setting, proceed to Step 2.

    2

    Turn the engine off. Move to the passenger side of the Rendezvous and open the door. Kneel next to the passenger seat so that you can access the underside of the dashboard. Remove the right-hand side insulator panel screws from below the dashboard, using a ratchet and socket. Remove the insulator panel from the Rendezvous and your work area.

    3

    Disconnect the electrical connector from the blower motor, using a flat-head screwdriver on the locking tabs if needed. Turn the Buick's engine back on while sitting in the passenger seat. Turn the fan speed and heat to their highest settings.

    4

    Turn the multimeter indicator dial to the volts setting. Insert the probes from the multimeter into the electrical connector. If you receive no voltage reading, there is an electrical malfunction between the blower motor fuse, resistor and control processor. If you receive a voltage reading, the blower motor is bad and needs to be replaced.

    5

    Installation of the blower motor electrical connector and insulator panel are the reverse of the removal processes. Tighten the insulator panel screws snug with a ratchet and socket.

Kamis, 22 April 2010

Signs and Symptoms of a Bad Lifter Flat Tappet

Lifter tappets aren't quite as simple as they seem at first glance. The hydraulic lifter is a sort of self-contained hydraulic system, utilizing a number of tiny components in order to control valve train movement. While replacing a collapsed lifter is simple -- at least compared to fixing the engine if you don't replace it -- don't rush into the job until you know what you're dealing with.

Lifter Basics

    Lifters are the small cylinders that sit in between a camshaft's lobes and the pushrods. With a hydraulic lifter, the bottom of the pushrod sits on top of a plunger, which in turn sits on top of a cylinder full of oil. Oil pressure pushes up on this plunger, stacking up slack, or "lash," in the system. In addition to taking up valve lash, most lifters stay slightly collapsed at low engine rpm, slightly reducing the distance that the valve opens to enhance bottom-end torque and while encouraging a smoother idle.

Symptoms

    When the plunger inside of a lifter fails, it'll fail to maintain oil pressure and will remain in a collapsed state at all times. When that happens, the lifter will fail to take up lash in the system, which causes parts inside to hammer against each other during initial contact. This hammering manifests as a very noticeable tapping that increases in volume and frequency with engine rpm. A bad lifter will throw off the affected cylinder's ability to move and burn air and fuel, which will typically lead to spark plug fouling and a consistent miss on that cylinder.

Consequences

    A collapsed lifter puts a great deal of stress on a vehicle's valve train, and the weakest link is usually the pushrod. Collapsed lifters can easily bend pushrods, which will subsequently fall out of the space between the rocker arm and the top of the lifter. Once a push rod falls out of the space, the very least you can expect is a dead cylinder. Worst-case scenarios include broken rocker arms, broken valves, cracked heads, a damaged cam or complete engine destruction depending upon what breaks, how it breaks and when.

Replacing Flat Tappets

    Replacing a collapsed lifter isn't quite as simple as you might think. While the shade-tree mechanic might simply pop the intake off and replace the faulty lifter, Ol' Scruffy isn't looking at the big picture. Cams and flat-tappet lifters are a matched set; they're broken in together at the factory to establish matching wear patterns. Putting a new lifter on an old cam is like trying to sharpen a set of ice skates with a waffle iron, and it's only a matter of time before that new lifter takes out your cam. But dropping in a replacement lifter is better than allowing lash to destroy your engine, so consider it as a band-aid fix.

Replacing Roller Tappets

    Roller-tappet lifters and cams are the exception here, since far less wear occurs when using a roller tappet. Generally, you can get away with replacing a single collapsed roller lifter without replacing the cam. This isn't true in all cases, but again, better to replace the lifter and risk a cam replacement later than to allow a $15 part to destroy your entire engine.

Rabu, 21 April 2010

What Makes My Truck Stall?

What Makes My Truck Stall?

There are a wide variety of problems that can cause a truck to stall out when you are driving or attempting to start it. Stalling can be annoying if your vehicle is not moving and highly dangerous if your vehicle is moving. A stall occurs when your engine stops running without you telling it to. If your vehicle is stalling, you should take it to a mechanic and have it properly diagnosed and repaired.

Stalling While Idling

    If your engine is stalling while you are sitting and idling, there are several different problems that could potentially be causing it. Stalling at an idle is often a result of air-flow problems in the engine, where your engine is not getting enough You should have your mechanic check all of your vacuum lines to make sure they are all connected properly and do not have holes in them that are affecting airflow and compression. If the vacuum lines appear to be in tact, the problem could be caused by your idle air control valve, exhaust gas recirculation valve or by built up engine deposits clogging these valves and causing them to malfunction.

Transmission

    Transmission or clutch problems can cause your vehicle to stall out while you are driving it. A malfunctioning clutch on an automatic transmission or a failing torque converter in a standard transmission can both cause your vehicle to stall out. If the stalling problems are related to your transmission, you will notice the truck stalling primarily when your truck is switching gears.

Fuel System

    Faulty or inconsistent fuel delivery can cause your vehicle to stall out. This may be caused by clogged fuel lines, a short in your fuel pump wiring or even a malfunctioning fuel pump that is intermittently turning on and off and not consistently delivering fuel.

Sensors and Electrical Problems

    If the stalling is accompanied by the check engine light turning on in your dashboard, there is a good chance your problem may be electrical or related to a fuse or sensor. Have your mechanic hook up a diagnostic code reading machine to your truck's computer and scan the computer for error codes. The error codes will indicate any sensors or relays that are not firing or operating properly and may in turn be causing your vehicle to run poorly and stall. Sensors control almost every component of newer model vehicles, and a poor fuel mixture, faulty ignition or imporper sensor readings can all cause stalling.

What Will Cause a Failed Wheel Bearing on a Car?

What Will Cause a Failed Wheel Bearing on a Car?

Wheel bearings -- even under the best conditions -- bear a great deal of stress. The smoothest road imaginable still sends minute vibrations through the tire, vibrating the bearings' internal components and accelerating wear. Bumps in the road send massive shock loads through the assembly, and cornering forces try to pull them apart on a consistent basis. It's almost amazing that they manage to spin or bear the car's weight at all.

Shock Loading

    Shock loading and lack of lubrication have to tie for first as the wheel bearing's primary assassins, but hard use can break them outright. Shock loading means subjecting the suspension to more sudden movement than it has to experience. This could happen over a long period of time, by operating the vehicle at high speeds over rough roads or no roads at all, or it could happen in one major blow by hitting a pothole, speed bump or curb with sufficient force.

Lack of Lubrication

    Even so-called "sealed" bearings require service from time to time, generally in the form of greasing. Grease installed at the factory will eventually begin to break down at a molecular level, which causes a reduction in its ability to lubricate and control heat buildup in the bearing. When the grease thins out, dries up or leaks out, the bearing material will begin to grind, wearing it away and increasing clearances in the bearing. These increased clearances allow the bearing to bind, further accelerating wear and eventually leading to failure. Bear in mind when servicing that using too much grease or the wrong type of grease will cause failure just as surely as using none at all.

High Speeds

    Sustained high speeds will do the same things to wheel bearings that sustained high rpm will do to a motor. The difference is that bearings don't have an oil-circulation or cooling system like the engine does, which limits how quickly they can get rid of heat. Sustained high speeds -- meaning anything past highway speeds -- will cause heat buildup in the bearing, thinning the grease and temporarily reducing its ability to lubricate. Thin grease accelerates wear. High speeds, over 100 mph or so -- can cause the bearing to reach thermal meltdown and fail entirely.

Sticky Tires

    Manufacturers engineer a car to handle only a given load, and the tires usually dictate how much of that load the chassis actually sees. Put simply, the tires are supposed to slip before anything else gives or breaks. Installing large, sticky tires will increase your car's handling, braking and acceleration limits, possibly past the chassis' ability to handle the forces involved. The car's suspension helps to protect the rest of the chassis, but wheel bearings are much closer to the action. This is particularly true when installing low profile tires, which flex less and transfer far more force to the bearings than they would otherwise see.

Huge Heavy Rims

    Now that 2003 has come and gone, somebody needs to tell the masses: huge, heavy rims aren't just passe, they're horrendously stupid where performance and longevity are concerned. Those 20-plus inch "dubs" add an enormous amount of unsprung weight -- weight not controlled by the suspension -- and rotational inertia, both of which constantly hammer on the bearings and suspension. The low profile rubber bands that "playas" tend to wrap around their spinning discs only exacerbate this problem, practically guaranteeing premature bearing and suspension failure.

How to Bench Test a Suzuki ATV Coil

The coil on your Suzuki ATV acts as an intermediary between the charging system of your engine and the spark plug. The coil sends the electrical impulse needed to fire the spark plug and to start the ignition process in the combustion chamber. When the coil starts to go bad, your engine will misfire and eventually just stop running altogether. If you have noticed misfires, you can bench test your coil. Fortunately, you can do so without actually removing the coil from the ATV.

Instructions

    1

    Locate the spark plug secured to the cylinder head on the engine. You will then locate a black spark plug wire extending from the top of the spark plug. Follow the wire from the spark plug to the coil. This is the easiest way to locate the coil.

    2

    Pull the black spark plug wire off the coil by hand.

    3

    Test the primary winding of your ignition coil. Locate the two wires connected to the bottom of the coil. Remove the wires from the coil by loosening the nuts that hold the wires on to the stud with a wrench. Make sure you mark the wires so you know which wire goes where when you reinstall them.

    4

    Place your multimeter or ohmmeter onto "Ohms" and place the red lead onto one metal stud that you removed the red wire from and then place the black lead onto the other metal stud. The readout on the multimeter must read between 0.5-Ohms and 1.5-Ohms. If not, the unit is defective.

    5

    Place the black lead of your multimeter into the hole vacated by removing the large black sparkplug wire. Place the red lead of your multimeter onto the stud where you removed the red wire. The readout on the meter must read between 6,000-Ohms and 15,000 Ohms. If not, the unit is defective.

    6

    Reconnect all of the wires, and start the ATV is possible. Allow the engine to warm up for five-minutes and then repeat the entire process. Be careful though, the engine is hot. In many cases, a coil will work properly with a cooled engine but will fail when the engine is hot.

How to Troubleshoot a Distributor Pick Up in a 1995 Ford Mustang

The distributor pickup in a 1995 Ford Mustang is much like a later model crank sensor in function, even though it is in the distributor. The pickup is an ignition-powered magnetic Hall effect sensor with its signal produced through the use of a round wheel with erect square blades, called shutter blades. As one of the blades passes in front of the sensor the voltage is high. When the blade passes, the empty slot between the blades causes a voltage drop. The increased voltage charges the coil and the voltage drop triggers the ignition control module to fire the coil.

Instructions

    1

    Raise the hood and locate the ignition control module on the front bottom of the distributor. It will have a multi-wire vertical plug.

    2

    Push a straight pin carefully through the top wire on the connector, which is the PIP wire. This is the signal to the ignition control module. Connect the black voltmeter lead to a good ground.

    3

    Connect the red voltmeter lead to the straight pin. Have a helper start the engine while you watch the voltmeter. As the engine is trying to start the voltmeter will show voltage spikes. Twelve volts will appear for a millisecond and drop to 0 in a repeating cycle. This is the signal. If no signal is present the sensor is bad. If there is a signal, check for spark at the spark plugs. If there is no spark, the ignition control module on the front of the distributor is bad, which is usually the case with a Mustang.

Selasa, 20 April 2010

Ford Focus Charging Problems

Ford Focus Charging Problems

The alternator in your Ford Focus is the heart of its charging system. The charging system converts mechanical energy into electrical energy that recharges the battery. Most defects in the charging system are a result of a faulty alternator.

Low Charge in Battery

    The battery provides your Focus with its start-up power. If the battery is losing its charge, the first thing to inspect would be its electrolyte level. Next, see if the alternator's drive belt needs an adjustment. Then inspect the terminal cables for any wear or corrosion. If all seems fine, you should proceed with inspecting the alternator.

Ignition Light Indicators

    If the ignition light doesn't go out when the ignition is switched off or doesn't light up when it's switched on, then the alternator may be faulty. There may also be a problem with the charging system's circuit.

Testing the Alternator

    One way to test the charging system and the alternator is to perform an on-car test. Test the battery first with a voltmeter with the engine off--the reading should be 12 volts. Test it again with the engine on--the reading should be between 13.5 and 14.6 volts. Turn on all electronic accessories. If the voltage reading drops below the minimum, the alternator may be faulty.

PO118 Code on a 2002 Chevy Blazer

The code P0118 is a computer-generated code set to indicate a particular failure within the system, which in this case is the coolant temperature sensor. The check engine light on the dash in a 2002 Chevy Blazer is also an indication that the car's computer is sensing a malfunction in one of its control or sensing devices that it operates. The check engine light responds to the engines emission and electrically controlled components. Mechanical failures or discrepancies have no bearing on the check engine light. Sensing a failure, the computer sets this failure to code for identification through the on-board diagnostics port. You need a code scanner to withdraw these codes from the vehicle.

Instructions

    1

    Open the hood of the 2002 Chevy Blazer and find the coolant temperature sensor on the side of the engine with the oil filler tube. The sensor is found in the cylinder head between the exhaust manifold runners. A failed coolant temperature sensor will send a signal to the computer indicating that the engine is overheating. In response to this signal, the computer will retard the spark to reduce the horsepower and response from the engine. It will also richen the mixture to cool the cylinders and prevent preignition that results in a drop in fuel economy.

    2

    Check the electrical connection on the sensor by pressing on the top tab and pulling it off. The code P0118 states that the computer senses too high a voltage through the sensor. This means that there is either a problem with the connector or the sensor has failed. Check the connector for cracks in the plastic or pushed-in female electrical plugs.

    3

    Inspect the immediate wiring around the sensor to see if it burnt against the exhaust manifold. Look at the sensor pins and ensure none are bent or missing. If a problem is found with the wiring, such as burn spots or plugs in the plastic electrical connector, repair the problem. A broken or cracked electrical connector must be replaced. Purchase a new pigtail -- length of wire with a new connector -- at an auto parts store. Bent pins in the sensor can sometimes be straightened however if the pins look compromised or bent too far, replace the sensor. If no discrepancy is found with the above inspections, replace the sensor.

    4

    Pull the electrical plug off the sensor. Make sure the engine is cold before removing the sensor. Place some Teflon tape around the threads on the new coolant temperature sensor.

    5

    Use a wrench to turn the sensor counterclockwise to remove it. When the sensor is almost out get the new sensor ready to install so very little antifreeze will be lost. Pull the sensor out and quickly install the new sensor. Tighten it down snugly and replace the electrical connector.

    6

    Move to the inside of the Blazer. Pick up the code scanner and plug its electrical connector into the OBD port. This port is below the dash to the left of the steering column.

    7

    Turn the ignition key to the On position without starting the engine. Press the key on the scanner marked Erase. The scanner will erase the code from the computers memory and turn out the check engine light.

How to Troubleshoot an Oil Leak in an Oldsmobile Alero

The Oldsmobile Alero engine relies on motor oil to protect it from the stresses of friction as the hundreds of internal working parts move past one another. The engine itself uses gaskets between each portion to prevent the oil from leaking out. Over time, the gaskets break down and begin to leak. When this happens, you'll need to troubleshoot the oil leak before you can perform the necessary repairs to correct it. If you have a leaking Oldsmobile Alero and basic auto-repair experience, you can handle this job.

Instructions

    1

    Remove the oil filler cap from your Alero's engine by hand. Make sure the engine isn't running before removing the cap.

    2

    Pour the automotive leak dye into the crankcase by hand. Put the oil filler cap back on the Alero's engine by hand.

    3

    Drive the Oldsmobile for 25 miles. Park the Alero and shut the engine off.

    4

    Open the hood and shine the black-light gun on all the upper and side portions of the engine visible from the top. The leak dye shows up as a glowing green substance when you hit it with the black light.

    5

    Look at the Alero's engine from underneath the car if you did not spot a leak from the top. Once you've pinpointed the glowing leak dye, you can visually trace it to the failed gasket.

How Do I Troubleshoot a Toyota FWD Pickup for Free?

Toyota is known for producing very efficient and long-lasting vehicles, generally requiring low maintenance. However, there are various minor maintenance issues and malfunctions that can be expected on any vehicle. Troubleshooting these common issues on your front-wheel drive Toyota pickup truck should be done immediately in order to ensure the continued performance and reliability of your Toyota. Note that if your Toyota pickup is suffering from a malfunction which triggers the "Check Engine" dash light, you should have the engine inspected by a certified dealer or mechanic, as this could indicate a more extensive and complicated engine malfunction.

Instructions

    1

    Ensure that all of the plastic interior panels are securely clipped in place if your Toyota is producing interior rattles under operation. Most interior panels are fastened in place by plastic clips, though larger panels may also be secured by Phillips head screws. Use the heel of your hand to bump the various panels in order to reproduce the rattling noises you hear while driving. This will allow you to locate any loose panels. Once located, ensure that the panel clips are tightly fastened, and tighten any securing Phillips head screws.

    2

    Inspect the air intake system at the front of your Toyota's engine bay for any signs of cracking or other damage. Damage to the intake system can lead to poor engine performance, as well as various air metering and emissions issues. Also ensure that any sensors or plugs into the air box and intake tube are securely connected.

    3

    Unfasten the clips that secure the plastic air box lid, and lift the lid free from the air box. Inside you will see the air intake filter. Examine the filter for any signs of damage or collected debris. Worn air filters can lower the performance of your Toyota, as the engine is not able to efficiently breathe air through the filter. Replace the filter with a new, factory unit if necessary, and reinstall the air box lid.

    4

    Examine all the various rubber lines routed throughout your Toyota's engine bay. These include intake vacuum lines, coolant lines, and/or various sensor connections. Since the engine produces high levels of heat under normal driving, rubber engine components are prone to cracking and breaking down over time. Damaged vacuum lines or intake system sensor connections can lead to various throttle issues, as well as lowered engine performance. Worn coolant lines are prone to bursting when the engine is in operation. Replace any worn rubber lines and connections with new, factory units.

    5

    Look for signs of smoke coming from the exhaust system when driving your Toyota. Generally, a smoking exhaust system indicates the development of more extensive engine issues. White smoke coming from the exhaust system is most often from the engine burning coolant, due possibly to a damaged intake manifold gasket or head gasket. Blue or black smoke most likely indicates that the engine is burning large amounts of oil, which can indicate a worn head gasket or damaged piston rings. Have your Toyota examined by a certified mechanic if the exhaust system produces smoke under operation, as such engine issues are likely to become more complicated if not repaired immediately.

The Causes of an Idle Surge

The Causes of an Idle Surge

Fluctuations in engine idle speed can be annoying and may even cause stalling at idle. Engine stalling can be dangerous, because power assistance is lost to the steering and brakes. Idle speeds below those specified by the manufacturer will affect the performance of the power steering pump, alternator and AC compressor. Emission control devices also require a minimum engine speed for effective operation. Surges that accelerate engine speed could cause unexpected vehicle movement.

Air Supply

    A clogged or obstructed air filter can cause surging at idle, and foreign objects can enter the filter housing at any time. Any debris in the filter or housing might restrict air flow to the engine enough to affect idle speeds. Clean the throttle body or carburetor venturi(s) after replacing a severely dirty air filter. Aerosol products designed for this purpose are available at any auto parts store. Instructions for use are on printed on the can.

Fuel Supply

    Fuel filters can become restricted and deny proper delivery at idle speeds. Mechanical fuel pumps may overcome restrictions and performance deficiencies at higher speeds. Incorrect idle speed settings or fuel mixture adjustments, and malfunctions in the fuel vapor recovery system can upset engine idle capabilities of carbureted engines. The appropriate fuel system cleaner added to the fuel tank can open clogged passages in injectors and carburetors that may be causing the surge.

Vacuum

    Any extra air entering the intake manifold will lean the mixture at idle and surging will result. A visual inspection of vacuum hoses may reveal cracked or leaking hoses. A short length of tubing can serve as a make-shift stethoscope to pinpoint any hissing noises heard on a running engine. Cracked or clogged positive crankcase ventilation valves can adversely affect engine idle quality. Idle solenoids or controls should be adjusted to specifications after vacuum leaks are repaired.

Engine Issues

    Professional assistance may be required.
    Professional assistance may be required.

    Ignition system problems can contribute to idle surge. Ignition timing and the condition of spark plugs and related components should be be checked before seeking professional assistance. Lack of compression, and valve timing and condition issues are complex to diagnose and usually affect overall performance, but can be more pronounced at idle speeds. Contributing emission system flaws may require advanced testing techniques or equipment. A visit to a qualified repair facility might be necessary.

Senin, 19 April 2010

How to Troubleshoot a No Start Condition in a 1995 Honda Civic

How to Troubleshoot a No Start Condition in a 1995 Honda Civic

You may find yourself in a situation when the engine of your 1995 Honda Civic will not start, and you either hear clicking sounds as you turn the ignition switch or none at all. Knowing how to troubleshoot your Civic, when it will not start, can help you save money, time and be on the road again. As of August 2010, the 1995 Honda Civic DX Sedan has a Kelley Blue Book suggested retail value of $3,060 in excellent condition.

Instructions

Basic Troubleshooting

    1

    Push the clutch down all the way to the floor if you have a manual transmission in your 1995 Honda Civic; otherwise, the starter motor will not crank the engine, resulting in clicking sounds or no sound at all. If your Civic is an automatic, make sure that the transmission is in "Park" or "Neutral."

    2

    Turn your key in the ignition to the "On" position and turn on your headlights. Look at the brightness of your headlights---dim lights or no lights mean you have a dead battery and need a jump start.

    3

    Examine the fuses if, after turning on your headlights, they appear bright. The fuse box is on the driver's side under the dashboard. If you do not see a blown fuse, which will look like a damaged, burned wire inside of the fuse, this means you may have a starter problem or a problem with the electrical circuit on the ignition switch. You will need to have your car towed to a technician in this case.

    4

    Watch the fuel gauge and make sure you have enough gas in your car if your motor sounds normal after turning the ignition switch to the "Start" position but the engine still does not run.

Jump Starting Procedure

    5

    Turn off all electrical accessories in your car, such as the air conditioner, stereo, heater and lights.

    6

    Place the transmission in "Park" or "Neutral" then set the parking brake.

    7

    Connect one end of a jumper cable to the positive "+" end of a booster battery and connect the opposite end to the positive "+" terminal on top of the battery in your Honda Civic.

    8

    Connect the second jumper cable to the negative "-"end of the booster battery and connect the opposite cable end to an unpainted bracket or bolt away from your car's battery. This will lower the risk of igniting hydrogen gas which your car battery always emits. The negative jumper cable will be black.

    9

    Start your car, disconnect the negative cable first from the grounding strap on your car battery then disconnect the cable from the booster battery. Disconnect the positive cable from the positive terminal on your car's battery then disconnect the positive cable from the booster battery.

    10

    Adjust the metal connections to ensure they have good metal contact if, after the jump start, the starter motor continues to run slowly after starting your car.

Automatic Transmission Is Slipping & Flushing Will Not Help

Flushing the automatic transmission, or removing old transmission fluid and replacing it with new fluid, can resolve many problems, such as slipping out of gear, according to AA1 Car. If slipping continues after a flush, however, the driver may be facing a more serious mechanical problem.

Causes

    Even after a successful transmission flush, mechanical problems can continue to cause slipping, excessive noise or inconsistent shifting. These problems may include a bad pump, a faulty valve body or a short in a shift solenoid. In some case,s a malfunctioning torque converter can cause problems that resemble transmission issues.

Troubleshooting

    Double-check the new transmission fluid level after a flush, since low fluid can cause slipping. Modern cars with on-board diagnostics (OBD) can provide trouble codes to diagnose some transmissions problems. Older cars require taking the car out on the road or performing pressure tests.

Repair

    If the reason for an automatic transmission's slipping problem goes beyond an individual part, such as a solenoid or valve, a transmission repair shop may have to tear down, inspect and rebuild the entire transmission. AA1 Car notes that this process can cost up to $8,000 (as of February 2011).

How Do I Clear Audi Diagnostics Codes?

How Do I Clear Audi Diagnostics Codes?

Whenever something malfunctions in an Audi's engine, the vehicle's computer generates a trouble code and activates a warning light on the dashboard. These codes are part of the On-board Diagnostics (OBD) system that has been in place since 1996. Virtually every major car brand uses diagnostic codes. Mechanics can retrieve the error message with a handheld scanner. Once repairs have been completed, clearing the OBD system is a relatively quick chore.

Instructions

    1

    Hook the code scanner up to the Audi's diagnostic outlet. You will find this beneath the dash on the driver's side.

    2

    Power up the scanner.

    3

    Turn the key in the ignition, but not all the way. You want the electrical system to come on, but not the engine itself.

    4

    Wait as the scanner and the Audi's computer communicate. The old code warning should show on the scanner.

    5

    Press "Clear" on the scanner. This should wipe the diagnostic message off the Audi's computer.

    6

    Repeat these steps if you want to double-check. The scanner should not detect a code if you try this a second time.

2002 Toyota Solara Fuel Problems

The 2002 Toyota Solara may experience problems with its fuel system. When it does, the check engine light may illuminate. A fuel-related problem may cause the engine to run rough.

Fuel Air Sensor

    Failures of the air-fuel ratio sensors can cause the check engine to illuminate. This system is also known as the wide range air fuel (WRAF) sensors. The WRAF sensors detect the leanness or richness of the fuel mixture. This allows the on-board computer to adjust the firing of the spark plugs. The repair cost of WRAF sensors is an estimated $377 for parts and $65 for labor (on average, as of March 2011).

EVAP System Failure

    The failure of the evaporative emission system (EVAP) is another reason why the check engine light will come on. The EVAP can cause a vacuum leak and the air-fuel ratio can run lean. Replacement of the charcoal canister or solenoid valve can turn the check engine light off. The cost of the repair of the EVAP system can range from $88 to $350 for parts and $19 to $65 for labor.

Idle Control Valve

    Debris can clog the idle air control valve. A clogged idle air control valve makes the engine run at very low rpm. The engine may stall when it is cold. The valve can either be cleaned or replaced.

Minggu, 18 April 2010

How do I Check the Map Sensor in an '88 Cherokee?

How do I Check the Map Sensor in an '88 Cherokee?

The map sensor in your Jeep Cherokee is part of a large network of sensors linked to the engine's Electronic Control Module. The ECM constantly monitors all engine activity through the supplied input of the various sensors. Through this gathered information, the ECM directs each component of of the Engine Control System to either maintain its settings or adjust as necessary.

Instructions

    1

    Raise the hood of your Cherokee. Locate the map sensor on the rear firewall.

    2

    Remove the electrical connector from the map sensor by pulling it straight down.

    3

    Connect the two outside-terminals of the map sensor to the matching terminals of the electrical connector. Use the two jumper-wires.

    4

    Attach the positive lead of the voltmeter to the center terminal of the map sensor. Connect the negative lead of the voltmeter to a solid ground.

    5

    Turn on the ignition; do not start the engine. The voltage typically reads 4.5 to 5.0 volts.

    6

    Start the engine and let it reach operating temperature. The reading on the voltmeter is usually different from the original base reading of 4.5 to 5.0 volts. The reading optimally increases and decrease with changes in engine speed. If the readings do not change, check the vacuum hoses for damage. If the hoses are undamaged, the sensor must be replaced.

Trouble Codes for a '97 Camry

Trouble Codes for a '97 Camry

On-board diagnostic (OBD)-II trouble codes cover the powertrain, body, chassis and network communications. While most codes are general in all post 1996 vehicles, Toyota has a separate set of supplemental codes. These codes are used in all Toyotas, regardless of model year.

Powertrain Codes

    Powertrain codes start with the letter, P" They cover the engine, fuel system and emissions. Toyota-specific codes start with P1, P30, P31, P32, or P33.

Body Codes

    Body codes cover many of the non-powertrain mechanical functions. These OBD-II codes always begin with the letter, B. This includes some braking components that are not governed by a Toyota's antilocking braking system. Toyota's supplemental body codes have B1 or B2 at the beginning.

Chassis Codes

    A Toyota's chassis system covers the vehicles electronics. This includes fuses, relays, wiring and anything requiring electricity to function. Chassis codes always start with the letter, C. Toyota's specific chassis codes begin with C1 or C2.

Network Communications

    Network communication OBD-II codes always start with the letter, U. A Toyota has many different diagnostic systems, and they must communicate with the vehicle's central computer. Toyota's supplemental network codes start with U1 or U2.

Accessing Codes

    OBD-II codes must be accessed with a hand-held code reader. The code reader attaches to the Toyota's data link connector (DLC). The location of the DLC varies by model within the 1997 model year. Generally, it is on the driver's side of the vehicle and beneath the dashboard.

Sabtu, 17 April 2010

How to Test Engine Coolant

The coolant in your engine provides two different types of protection to the engine. Its first job is to absorb heat generated in the engine by combustion and transfer it to the outside air throughout the radiator. The second job of the coolant is to lubricate the bearings in the water pump and prevent corrosion in the system. Both areas of protection should be tested when the coolant condition is inspected during normal vehicle servicing.

Instructions

    1

    Allow the engine to cool completely to prevent painful injuries caused by coolant boiling out of a hot engine when the radiator cap is removed.

    2

    Remove the radiator pressure cap. The cap is located either on top of the radiator, on top of the coolant reservoir or on top of the thermostat housing. Press down and twist the cap counterclockwise, similar to opening a child-proof medicine bottle, then set the cap aside.

    3

    Squeeze the rubber bulb on a coolant hydrometer and submerge the hydrometer's tube into the coolant. Release the bulb to draw coolant into the hydrometer up to the full line marked on the body of the unit.

    4

    Hold the hydrometer level and read the temperature marked on the side of the unit that the arrow in the hydrometer is pointing at. This is the coldest temperature that the coolant will withstand without freezing. The coolant should resist freezing at a temperature well below what is the lowest expected temperature in the winter.

    5

    Insert a coolant test strip into the coolant, remove the strip and shake any excess coolant off. Wait 15 seconds and compare the color of the test strip with the gauge on the side of the bottle that the strip came in. If the color indicates the need for replacement, the lubrication/anti-corrosion properties of the coolant have dissipated. Failure to replace the coolant at this point can result in premature water pump failure.

Actron Scanning Tools

Actron is a company that specializes in car diagnostic tools, including scan tools, electrical testers and battery tester. A scan tool allows you to run diagnostic tests on your vehicle to determine what is wrong, and you can also use these tools to view and/or erase fault codes, including the check engine light. All of these tools are compatible with on-board diagnostic II (OBD II) systems.

AutoScanner Plus

    The CP9580 AutoScanner Plus with CodeConnect allows you to scan for fault codes, and it will also prioritize fixes based the make, year and model of your vehicle. The CodeConnect feature allows you to view detailed information about the error codes, and the tool will let you know whether there is additional information available about that particular error. Other features of this tool includes that you can capture real-time information about your engine, and it also allows you to view and erase anti-locking braking system (ABS) codes. You can check on the current state of your OBD system, and you can output any diagnostic information to your personal computer. It also comes with a universal serial bus (USB) port, which allows you to connect this device to your computer. As of 2010, this tool costs $299.99.

AutoScanner CP9575

    You can use this tool on both OBDII and controller area network (CAN) protocol vehicles, and this tool allows you to determine whether or not your system is performing properly based on real-time information. It comes with a screen that allows you to see code information, and you can also view freeze frame and drive cycle information. Other features of this tool are that you can view the current state of your OBD system, and you can view current and upcoming diagnostic trouble codes (DTCs). This tool also has a USB port, and it is compatible with all vehicles made from 1996 to the present. As of 2010, this tool costs $144.99.

Elite AutoScanner

    The Elite AutoScanner CP9185 costs $429.99 in 2010, and both consumers and professionals can use this tool. It allows you to create visual graphs of your engine data information, and you can output this information to your computer. You can capture and play back vehicle error data, and it comes with a USB cord, which allows you to connect it to your computer and obtain software updates from the company website. This tool is compatible with most Ford, General Motors and Chrysler vehicles, and it is compatible with CAN protocol vehicles.

Jumat, 16 April 2010

Why Are My Front Tires Vibrating?

Why Are My Front Tires Vibrating?

Charles Goodyear's 1844 invention of vulcanization -- the process that makes rubber more elastic and resilient to swelling -- launched the introduction of rubber tires. The vulcanization process was so important to tire development that one of the largest tire manufacturers adopted his name -- Goodyear. Throughout the years, automotive tire manufacturers have made more technological advances, including Kevlar reinforcement, silica additives and high-efficiency rubber -- however, they are still not impervious to vibrations.

Tire Separation

    Manufacturers assemble modern tires with steel and nylon bands under the rubber to provide reinforcement. Without these bands, the tire would expand and contract like a balloon and not be capable of supporting a fraction of the weight it needs to. These bands, on occasion, can separate, allowing the air inside the tire to press against the tire's rubber, creating a bubble in the tire. If the bubble is on the tread, the bubble may cause a vibration from the tires. This vibration increases with the speed of the vehicle.

Uneven Tread Wear

    Passenger tires require periodic maintenance, including alignment and rotation. Rotating the tires changes the rotational pattern of the tires and the alignment adjusts the angle that the wheels set -- camber, caster and toe. Failing to rotate the tires at the specified intervals or periodically checking and adjusting the alignment, may result in a choppy tire wear. This choppy tire wear can result in a vibration from the front tires while driving.

Flat-Spotted Tires

    Flat-spotted tires are when a section of the tire's tread is flat instead of rounded. This flat spot may result from brake lock-up or manufacturing defects. If on a front tire, a flat spot can result in a vibration from the front wheels. The intensity of the vibration depends on the size of the flat spot and increases with the speed of the vehicle. A loud thumping sound may accompany a large flat spot.

Unbalanced Tires

    During the manufacturing process, most tires develop a heavy spot -- one section of the tire is heavier than the rest. In nearly all cases, a tire installer must attach a small weight to your vehicle's rim to counter the heavy spot in the tire -- typically 0.25 to 3 ozs. If the tire installer forgets to balance your tire, or the weight falls off, you will feel a mild vibration from the tires. You may only feel the vibration at certain vehicle speeds and the vibration may be slight.

    Do not be alarmed if you do not see wheel weights on your rims, as not all tires require balancing. In rare instances, the heavy spot in the tire may be so light that balancing is not needed.

Kamis, 15 April 2010

What Are the Causes of a High Hydrocarbon Reading During a Smog Check?

A requirement in many areas now is an emissions test to determine whether your vehicle meets the minimum requirements, with regard to environmental concerns such as air pollution. However, an emissions test can also be an indicator of a vehicle's performance and possibly bring attention to a problem, such as poor fuel economy, that might have otherwise gone unnoticed. Some emissions problems are relatively simple to diagnose, while others are often more complex, requiring major repairs that can be quite costly. Hydrocarbons, which are composed of raw, unburned fuel, are one of the things an emissions test is designed to measure. A high hydrocarbon reading can be the result of numerous problems that can all lead to incomplete combustion.

Timing Issues

    Incorrect engine timing can be a major cause of a high hydrocarbon reading. Since timing is measured in degrees, an incorrect setting can affect the cylinder firing and result in both a functional failure and increased hydrocarbon emissions. Late-model vehicles are not likely to have a distributor, which is used to adjust engine timing. In such cases where the timing is controlled by a computer, any problems would involve checking the vehicle's computer control system and related components to narrow down the possibilities and replace any necessary parts.

Ignition System

    While many modern vehicles no longer rely on distributor-type ignition systems, they still include ignition coils, spark plugs and spark plug wires. Any of these ignition components that fail will certainly result in a high hydrocarbon reading, since some of the fuel can remain unburned. Due to the high voltage that flows through the ignition system, carbon buildup will eventually form and can adversely affect their performance.

Fuel Mixture

    Problems, such as leaking vacuum hoses and leaking gaskets, that permit unmetered air to enter into the combustion chambers via the intake manifold can also affect hydrocarbon readings. This causes a misfire, due to a lean fuel/air mixture. Since vacuums are so important to engine operation, any defective components that rely upon it, such as a brake booster, can create very large vacuum leaks and consequently high hydrocarbon readings.

Catalytic Converter

    The purpose of a catalytic converter is to continue to burn any raw fuel that manages to get as far as the exhaust system, before it escapes into the air outside. As the last line of defense, if it were to fail, the probe that is placed in the tailpipe for the smog check would undoubtedly reflect a higher hydrocarbon reading. Problems with catalytic converters can range from being plugged up to having an actual broken substrate inside.

Air Pump

    Although air injection pumps are not present on all vehicles, they too can produce a high reading when faulty. Their purpose is to inject clean air into the exhaust as it comes out of the exhaust manifold. Introducing oxygen at this point enables the fuel mixture to burn more completely, thus reducing any hydrocarbons. Potential problems can occur within the system's plumbing, valves, lines and hoses, as well as in the pump itself.

Low Compression

    The least common cause of high hydrocarbons is low cylinder compression. However, problems of this sort involve disassembly of part or all of the engine itself. Burned valves, defective guides and seals, worn piston rings and even blown head gaskets can all be causes of low compression. In this case, however, it is quite likely that a rough idle condition will have been apparent from the start.