Minggu, 31 Mei 2009

How to Read Data From a Scan Tool

How to Read Data From a Scan Tool

Car code scanners let a mechanic or car owner understand and "read" the signals stored in a car's onboard computer. Using a computer language referred to as onboard diagnostic code, the scanner pulls the information from the car's computer memory and translates it to code numbers for the user. This information then helps diagnose what may be causing car operation problems, depending on which signal is being given by the car's sensors.

Instructions

    1

    Purchase an OBD-II compliant code scanner for vehicle diagnostics either at your local automotive part store or online using your computer and Internet connection. Purchase a scanner that displays both the car code and category for best results. Some scanners provide only the code.

    2

    Open your car driver's side door and sit in the driver's seat. Find the code junction panel underneath the steering wheel or on the side of the console and open it. Do not confuse it with the fuse panel. Open the panel. Insert the connection end of the scanner into the junction panel for code reading.

    3

    Insert your car key into the ignition and turn the car to the "ON" position but don't start the car engine. Watch the scanner power up and read the car's computer. Allow the scanner time to process the codes saved on the car memory until they display on the scanner screen.

    4

    Use a notepad and pen to jot down the codes displayed on the scanner in case the car turns off. Turn the car off and disconnect the scanner when finished.

    5

    Refer to your code reference book or a website such as OBD-Codes to determine what issue the codes show. Use the code number to confirm the type of signal and warning message. Use a website or your code reference book to get a detailed description of the potential problem and which sensor is giving the signal.

How do I Set an Alarm on an Infiniti I30?

How do I Set an Alarm on an Infiniti I30?

The Infiniti I30 comes with a factory-installed alarm. A properly set alarm gives you peace of mind from knowing that your I30 is secure. It also warns potential intruders to stay away from your Infinti. The process for setting the alarm is the same in Infiniti I30 cars of all model years.

Instructions

From Outside the Car

    1

    Shut all doors, the hood and the trunk. Make sure the hood and trunk are locked.

    2

    Lock the doors by pressing the "lock" button on the remote controller. You can also lock the doors with the key.

    3

    Wait for the "Security" indicator light on the dashboard to glow steadily and then start blinking. You have successfully set the alarm.

From Inside the Car

    4

    Ensure the trunk and hood are shut and locked. Lock all doors.

    5

    Insert the key in the ignition and leave it in the "Off" position.

    6

    Wait for the "Security" indicator light on the dashboard to glow steadily and then start blinking. You have successfully set the alarm.

Sabtu, 30 Mei 2009

1992 Subaru Legacy Front End Problems

1992 Subaru Legacy Front End Problems

The 1992 Subaru Legacy is considered by many automobile review and reports websites as being a reliable vehicle, but some reports have come to light about the front end problems some Legacy owners are experiencing. The front end of the Subaru is designed with mechanical components that can wear, come loose or break under normal driving conditions, and the problems that develop from front end problems can be diagnosed by the way the Legacy operates.

ABS Failure

    The anti-lock braking system (ABS) can cause a front end problem on the 1992 Subaru Legacy. A minimum of nine reports have been cited about the ABS pump continuously running, causing the front end of the Legacy to vibrate or shimmy when the brakes are engaged. This continuous running of the ABS pump causes the brake system to eventually fail, leaving the Legacy operator without brakes. This front end problem can create an accident situation because of the lack of stopping power. The ABS pump must be replaced, and the brake calipers, brake pads and brake rotors need to be inspected to determine if any damage was done to these ABS components because of the pump problem.

Front End Bushings Wearing

    The front end bushings can prematurely wear on the 1992 Subaru Legacy, causing front end problems. When the front end bushings begin to wear, the Legacy will become hard to turn or pull to one side under normal driving conditions. The bushings are the front end components that allow the tie rods to turn the tires via the steering wheel. No specific reason has been given for this premature failure of the front end bushings, but some reports state that the bushings are not properly lubricated, or debris from road contaminants seep into the bushings, causing them to corrode and wear prematurely. The Legacy needs to have the bushings replaced in order to correct this front end problem.

Front End Noise

    The biggest complaint about the 1992 Subaru Legacy is excessive noise coming from the front end of the automobile. This front end noise problem is attributed to several front end problems, such as loose bolts, lack of front end lubrication and broken front end components. No specific cause has been attributed to this front end noise; but when front end noise does develop on the Legacy, the vehicle needs to be taken to an automotive technician as soon as possible. This noise can indicate something minor, such as lack of lubrication, or a major problem, like a broken tie rod. Either condition needs attention immediately, or accident situations can develop, and more expensive repairs will be required.

How to Troubleshoot a 2000 F-150's Ignition Switch

The ignition switch on a 2000 Ford F-150 is located on the lower part of the steering column. It has a rectangular shape and is operated by an L-shaped rod running from the ignition key through the column housing with a 90-degree angle protruding through the cover entering the bottom of the switch. The rod is pushed or pulled by the rotation of the key, which activates the different functions of the switch.

Instructions

    1

    Remove the lower dash cover under the steering column using a screwdriver. Remove the three nuts in the column support bracket under the column using a socket. Allow the steering column to lower, and rest it on the driver's seat.

    2

    Grab the ignition switch and make sure it is tight by trying to move it up or down. If it is loose, move it up as far as possible, followed by downward motion. Move the ignition switch to the middle position between the upper most movement and the downward most movement; tighten the two bolts with a socket. Turn the ignition switch on.

    3

    Wiggle the electrical plug in the switch to ensure tightness. Check the fuse in the fuse box on the driver's side fenderwell marked ignition. Replace if necessary and retry. Attach the voltmeter's black ground lead to one of the steering column support studs for a good ground. Using the voltmeter's red lead, probe the red wire going into the ignition switch -- it should have battery voltage. If not, the battery is dead or has a bad terminal.

    4

    Turn the ignition key to the run position without trying to start the vehicle. Probe the remaining wires for voltage. There should be voltage to two more wires. The yellow wire is for the starter and should not have voltage at this point. If no voltage is found on the other wires, the switch is bad and needs replacing.

    5

    Probe the yellow wire while the key is held in the start position. Battery voltage should be present when the switch is in this position. If no voltage is present the switch is bad. If there is voltage the problem is elsewhere.

My Honda CM200 Won't Start

The Honda CM200 is a four-stroke street bike that was popular in the early and mid-1980s. It is a fairly easy motorcycle to learn to ride and made a good starter street bike for many people. Like any motor vehicle, when the bike gets older you may find that it is prone to some problems with starting. However, most of these problems can be fixed by the owner in his own front yard or garage.

Instructions

    1

    Check the fuel tank. If the vehicle is out of gas it will not start. It may not even start if there is a small amount of fuel. Add fuel and see if the motorcycle starts. Check the battery's charge with a battery meter. If you do not have a meter, most parts stores will check the battery for free.

    2

    Check the throttle cable. They will wear and rust over the years. To examine the cable move the throttle to see if it moves the switch on the carburetor. If it does not, then the cable may be broken. If the throttle cable is broken then replace it.

    3

    Check the spark plug. Remove the spark plug and examine it. It is best to replace a spark plug every spring, but if you have not and it has a dark carbon buildup then it will need to be replaced. Purchase the specific spark plug and replace it in the spark hole. Do not overtighten because the plug may break.

    4

    Check the fuel filter. It will be located on the fuel line just before the engine. Remove it and replace. This is another part that should be replaced every spring. It will fit right onto the hose for the fuel line. Just push the fuel lines back onto the filter holder.

    5

    Check the fuel valve. It may be stuck in a closed position. If this is the case replace the valve. This will require a Phillips screwdriver to replace. This valve attaches to the fuel line, and you will want to clamp the fuel line to prevent a fuel spill during valve replacement.

    6

    Attempt to push start the motorcycle. Start by pushing it to about 10 miles an hour, and then hop on the bike and engage first gear. You will have to throttle it to get fuel into it. If it does not start, then you may have serious problems that will require a professional mechanic to examine the crankcase and piston.

Why Do Turbine Engines Surge?

Why Do Turbine Engines Surge?

The Encyclopedia Britannica tells us turbine engines develop power "by accelerating the turbine exhaust flow through a nozzle." The rotating compressor blades get their power from those burning exhaust gases, which spin another set of blades attached to the compressor blades via a shaft. A lot can go wrong with this apparently simple mechanism, including the dreaded "compressor surge."

Axial Flow vs Turbocharged Engines

    Also known as a "jet" engine, the axial-flow design is one of the simplest of all engines. In an axial-flow engine, air flows through the compressor blades and into a central combustion chamber, where the gases pressurize and shoot out through the exhaust turbines. A turbocharged engine is very similar in concept, except it uses an engine block and pistons in place of a simple central combustion chamber. Air flows through the turbine compressor blades, combusts with fuel in the engine and goes out through the turbo's exhaust turbines.

Surge Basics

    No matter what kind of turbine engine you're talking about, the definition of surge is always the same. Surge happens when pressure after the compressor blades -- in the combustion chamber in an axial-flow engine or the engine block on a turbocharged engine -- exceeds the blade's ability to compress it. Under normal conditions, the turbine blades will only compress air by a certain amount; after that, that they simply stop working. But if pressure suddenly spikes behind the blades, or suddenly drops ahead of them, then the direction of airflow will reverse. This stops the compressor blades in their tracks, which can result in massive damage.

Surge in Axial-Flow Engines

    Surge in axial engines isn't completely understood, but it tends to happen while air velocity through the engine is low and pressures inside the engine are high. If you think of a jet engine as you would a regular engine, then think of the jet's surge point as its compression limit for a given displacement. If the compressors squeeze the air too hard, pressures inside of the combustion chamber will go up, creating an increased likelihood of surge. A certain amount of surge is normal during start-up, when engine rpm is too low to keep air going in one direction, and is more likely to happen if rpm drops too quickly or if excess backpressure builds up as a result of the exhaust nozzle closing too far for a given rpm.

Surge in Turbocharged Engines

    Turbocharged gas piston engines are especially susceptible to surge because of the throttle plate. While accelerating, your engine sweeps up through from a lower rpm to a higher one. When you hit the engine's redline and the turbo is running at full speed, you must lift off of the accelerator briefly to shift. When the throttle plate snaps shut, air comes to a screeching halt and velocity drops to near nothing. Pressure in the boost tube spikes, and air goes shooting backward out of the turbo.

Solutions and Consequences

    Surge can be avoided in jet engines by keeping engine rpm and airflow within its maximum efficiency range, and by keeping the engine out of aerodynamic stall via forward movement. In a turbocharged engine, a spring-loaded blow-off valve in the intake tube helps to vent pressure spikes during shifting, before they have a chance to induce surge. If you've ever heard an import drive by and emit a pronounced whistle between gears, then you're hearing the signature sound of an externally vented blow-off valve. Allowing either an axial-flow or turbocharged engine to go into surge will net the same results: broken or shattered compressor blades, bearing damage and quite possibly an exploded compressor.

Senin, 25 Mei 2009

My GMC Pickup Won't Start

My GMC Pickup Won't Start

General Motors Corporation (GMC) is a division of General Motors, Inc. that manufactures a variety of pickups, vans, and sport utility vehicles. As of 2010, GMC is manufacturing three pickup lines: the Sierra, the Sierra Heavy Duty, and the Canyon, though they also have some retired pickup lines. Just as with other pickups, the GMC pickups might require troubleshooting on occasion because of problems starting. There are a few checks you can make before calling a professional.

Instructions

    1

    Try to start the engine by placing the key into the ignition switch of your GMC pickup and turning it. If the key does not turn at all, the steering column might not be locked. Turn the steering wheel left and then right. You should hear a click when it is locked. Turn the key again.

    2

    Turn the key to the "Accessories" mode. Look at the fuel gauge. If the fuel is low or empty, the vehicle will not start properly. If this is the case or you are unsure of whether the gauge is accurate, add a gallon of the appropriate fuel to the fuel tank. Try to start your GMC pickup again.

    3

    Complete a simple diagnostic check on the battery. With the key in "Accessories" mode, turn off the interior lights or headlights. Look to see if the lights are lit up. If they are not turning on in "Accessories" mode, the battery is likely the problem. The battery of your pickup might need to be jump-started, charged, or even replaced.

    4

    Check the fluid levels. Read your owner's manual to locate the transmission fluid, coolant and oil dipsticks. Pull the lever, and open the hood. Check the levels of each fluid, making sure each is filled to the appropriate level. If fluids are too low or empty, the engine could be damaged or have trouble starting.

    5

    Listen for any sounds that might indicate what the problem is when attempting to start the vehicle. If your pickup starts briefly but then shuts off, there might be a problem with the fueling system. Clicking noises can mean your starter needs to be replaced, and no sound can mean your ignition switch needs to be replaced.

    6

    Tow your GMC pickup or have it towed to a garage or dealership that will be able to perform more extensive diagnostic testing and repairs. Contact a GMC dealership with questions about the specific mechanics of a GMC pickup.

Minggu, 24 Mei 2009

How to Test Car Battery Voltage

How to Test Car Battery Voltage

The state of your car battery determines your vehicle's ability to start and its electrical system's performance. When the battery begins to cause problems for your vehicle, you should to test its storage and starting capacity. A simple test with the proper electrical metering equipment will determine the current state of your battery and its potential for replacement.

Instructions

    1

    Apply the parking brake of the vehicle.

    2

    Open the vehicle's hood.

    3

    Turn on the voltmeter. Set the negative lead of the voltmeter to the ground terminal post of the battery. Press the voltmeter's positive lead to the positive battery post. Read the display to determine the voltage stored in the battery. A normal battery level will remain between 12.5 and 12.8 volts.

    4

    Start the vehicle. Check the draw on the battery while the vehicle is starting. Hold the leads to the battery as the vehicle is running to determine the functionality of the vehicle charging system. Turn off the vehicle.

    5

    Watch the voltmeter display as the vehicle sits. Replace the battery if the voltage drops steadily after the engine is turned off.

The Window Won't Open on My 2002 Mini Cooper S

The Window Won't Open on My 2002 Mini Cooper S

A car window stuck in the up or down position is frustrating but it can happen in the MINI Cooper S model. The car may have to be taken to a dealership or repair shop to have the motor replaced but first you can try a couple of things to fix or diagnose the problem.

Instructions

    1

    Insert the key and turn the ignition to "On" without starting the engine.

    2

    Press and hold the window switch in the up position for 10 or more seconds. This will reset the window position sensor and may make the window move again.

    3

    Test the window to see whether it works. If it does not, move to the next step.

    4

    Close the door and tap the inside of the door firmly, just above the speaker. This can put the wires back in contact with the back of the motor.

    5

    Test the window. If it still does not work, move to the next step.

    6

    Replace the window motor. This is not a difficult process to do yourself but the best option is to take the car to a repair shop or MINI Cooper dealer.

How to Check the Coil on a 1990 Honda Civic LX-1500 cc

The coil on a 1990 Honda Civic is incorporated in the distributor. The coil requires the crankshaft sensor and the ignition control module in order to operate. The crankshaft sensor signals the position of the number one piston relative to its compression stroke. The ignition control module uses this signal for firing the coil. Given the frequency of failures in all three, the ignition control module is the most frequently replaced, followed by the crank sensor and the coil. Check all three if the car will not start.

Instructions

    1

    Detach the distributor cap using the Phillips screwdriver to remove the screws securing the cap.

    2

    Remove the Phillips screw in each of the two coil terminals. The white and blue wire is the negative terminal. The black and yellow wire is the positive terminal.

    3

    Place the volt or ohmmeter on the ohm scale. Probe the two terminals using one probe on each terminal. The ohmmeter should display 0.6 to 0.8 ohms. If the reading is higher or lower, replace the coil.

    4

    Place the red probe on the black and yellow wire terminal and the black probe in the coil tower. The reading displayed must be 13,200 to 19,800 ohms to be good. If the reading displayed is different, replace the coil.

Sabtu, 23 Mei 2009

How to Troubleshoot the Transmission on a 1998 Dodge Intrepid

How to Troubleshoot the Transmission on a 1998 Dodge Intrepid

You might think that you need to take your Dodge Intrepid to the transmission shop if it's not working properly. It's possible that the trouble you are having with the transmission can be simple to repair. Troubleshooting your Intrepid transmission can be done right at home is a few easy steps and without much mechanical ability.

Instructions

    1

    Start up your Dodge and drive it around the block a couple times to warm up the transmission.

    2

    Lift up the hood and find the transmission filler tube and dipstick. It will be located on the driver's side of the engine.

    3

    Pull out the dipstick and wipe it off with the cloth. Look at the fluid and make sure its not burnt or a very dark color. The transmission fluid should be red in color. Put the dipstick back in the tube and pull it out again. Check the level to make sure it is at the full position. Low transmission fluid can cause the Dodge Intrepid transmission to fail.

    4

    Set up the ramps in front of the front tires and drive the car up onto the ramps. Set the parking brake. Place the tire block behind one of the rear tires.

    5

    Lie down under the car so that you are looking up at the transmission. The transmission is connected directly to the rear of the engine.

    6

    Use your work light to study the transmission. Look for any loose connections or leaks. Loose connections and leaks will cause your transmission to malfunction.

Kamis, 21 Mei 2009

My VW TDI Won't Start

My VW TDI Won't Start

Volkswagen is a car manufacturer mostly known for its Beetle and Bus models from the 1960s. In recent years, it also has manufactured other popular models such as the Golf, Jetta, Passat and several TDI models. If you are the owner of a VW TDI and are unable to start your car, there are a few ways to diagnose your problem before bringing your VW TDI to a mechanic.

Instructions

    1

    Check the battery terminal connections. Open the hood of your VW TDI, and look at the terminal connections. The terminal connections are the red and black cables that connect to the positive and negative ends of your car battery. If your terminal connections are loose or corroded, reattach the terminal connections.

    2

    Jump start your battery. If your car won't start, your battery might simply need a jump start to get some power back in its system. To jump start your car, you need another car and a set of jumper cables. Before connecting the jumper cables, make sure the red and black ends do not cross while you are using them. Connect one set of the red and black ends of the jumper cable to the second car's battery while it is running, and the connect the other end of the jumper cable to the red and black connections on your VW TDI's battery. After a few minutes, your VW TDI should have enough juice in the battery to start. Turn over the ignition; if your car still won't start, your battery is likely dead.

    3

    Replace the starter. If your battery connections are secure and you have tried jump-starting your car, you might need to replace the starter. The starter helps turn over the engine to get it running. If your starter is broken, you will either hear a clicking noise or no noise at all when you try to turn your car over. If this is the case, replace the starter.

Reasons for Low Transmission Fluid

Reasons for Low Transmission Fluid

There are many reasons transmissions can leak. Seals can break, bolts can come loose, and gaskets can deteriorate. It is essential to inspect the transmission to ensure there are no leaks. When the transmission fluid gets low enough, the vehicle will fail to shift, and this will result in an expensive repair bill.

Main Seal

    The rear main seal is located between the engine and the transmission. When the seal starts to crack or deteriorate, this will cause transmission fluid to leak out between the engine and the transmission. The fluid level will slowly decrease as the fluid is pushed out from the cracks in the main seal.

Transmission Pan Gasket

    The gasket that seals the transmission pan to the bottom of the transmission could eventually cause the fluid to leak out. Replacing the gasket is necessary when the transmission fluid is replaced. When the pan is dropped, the gasket needs to be scraped away to ensure the new gasket goes on smoothly. If the old gasket is not scraped away properly, this will cause fluid to leak out of the pan.

Transmission Pan Bolts

    Most transmissions require that their bolts be tightened to a particular torque to ensure the bolts are tight enough to produce a seal to keep the fluid in the pan. If any of the bolts work loose, the fluid will eventually leak out and cause the transmission to have serious mechanical issues.

Transmission Lines

    Most automobiles have a transmission cooler located at the bottom of the radiator. The fluid is sent from the transmission and circulates through the bottom of the radiator then back to the transmission. The lines are made of aluminum or steel and are very durable. Sometimes these lines can break and cause fluid to drip out. The lines can break at the threading or along the line itself.

Torque Converter

    The torque converter is a hydraulic pump that pushes the fluid through the transmission and ensures the fluid circulates through the transmission. The torque converter can break down, and the fluid will eventually leak out. This will require replacement of the torque converter.

Cables and Wiring

    The fluid can also leak in any area that has something installed in the transmission. The speedometer cable is plugged into the back of the transmission; and after a while, the seal may get broken and cause fluid to leak out. There are various other areas, such as the kickdown lever, servo covers, side cover, filler tube and electrical connections, that have gaskets that can leak and cause the transmission fluid level to drop.

How to Troubleshoot My Car That Will Not Start When Hot

Hot weather can quickly overcome a car in a number of ways. The coolant can be dissipated if not monitored regularly. The battery can be overtaxed with running the car and air conditioner excessively. Even the fuel system can work against you, flooding the engine before starting. The trick to solving the problem is to methodically go through potential problems to find the culprit.

Instructions

    1

    Turn the key ignition on to see if the car still won't start. Look at the dash panel to confirm if the battery has enough juice to even display in the car or if it is completely dead with no electrical power whatsoever.

    2

    Open the car hood, and prop it up if necessary. Bump the battery with your shoe via good whack and try the ignition again (the bump may reset a faulty connection). Leave the key in the ignition in the "on" position and the radio turned on to hear it while checking the cables around the battery. Use a flashlight if it's too dark to see. Identify the last cable touched if the radio starts up.

    3

    Clear the engine from being flooded by pressing your foot all the way to the floor (this stops the throttle sensor from adding fuel at all). Start the ignition for not more than 15 seconds to air out the spark plugs, which may be fouled by sitting fuel. Let the car sit for a few seconds and try to start again (it should work if the problem is fouled plugs).

2001 Ford F150 Cold Start Problems

The Ford Modular engine and its drive systems -- like those of any other vehicle -- run best when hot. Engines and batteries have an ideal temperature range where their metal and interior parts expand to exactly the dimensions that they're supposed to be. When parts get older, the tolerances that depend on parts that are hot and running could cause problems when everything's cold.

Low Battery Amperage

    Car batteries don't typically fail outright; they sort of fade away to the point that they become useless. As a battery gets old, its lead plates thin and degrade, which reduces the amount of amperage that can pass from one to the other. Cold engines are harder to start than engines already at optimal operating temperature, and your battery may not provide enough amperage to run both the starter and the ignition system. Take your battery to any chain auto parts store and have them check the battery's output under load.

Bad Fuel Pump

    Older fuel pumps are more sensitive to voltage changes than newer ones, and may not provide adequate pressure when starting. When you start the truck, most of its current and voltage go to the starter, depriving other systems of the power that they need. This is especially true for vehicles like the 2001 F-series, where fuel pump output pressure varies directly in proportion to voltage. The problem may be low battery charge, but the solution is to buy a new fuel pump and pump regulator. Bear in mind alsol that a clogged fuel filter can manifest similar symptoms.

Bad Ground

    The starter is your truck's most energy-hungry appliance, and places more load on the system than most other accessories put together. A solid connection between the starter power terminal and the battery is only half of the equation; your truck needs an equally strong ground cable to complete the circuit. Old, frayed and loose ground cables will create a restriction in circuit; add in the demands of an ignition system and fuel pump and you create a situation in which the truck may run fine most of the time yet prove very difficult to start.

Excess Air

    The Mod motor's computer can compensate for a certain amount of excess air under running conditions, but it might not prove as adept when the engine is cold. Engines have choke plates because they need a richer fuel mixture to start when cold; vacuum leaks, a maladjusted throttle or throttle position sensor or stuck-open idle air control valve will introduce more air than the engine needs or the computer can compensate for under idle conditions when cold. Additionally, a bad temperature sensor will trick the computer into thinking the engine is warm, so make sure that's working.

Rabu, 20 Mei 2009

How to Test the Camshaft Position Sensor on a 1997 Ford F150

How to Test the Camshaft Position Sensor on a 1997 Ford F150

The camshaft sensor in your 1997 Ford F-150 supplies a signal to the on-board computer that is used to calculate and trigger the fuel injection system. The models equipped with the V-6 engine use a hall-effect sensor that supplies an a/c signal that varies between 0 and 5 volts, depending on the position of the camshaft as it rotates. The models equipped with the V-8 engine use a variable-reluctance sensor that provides a digital "on/off" signal as the camshaft rotates. Each type of sensor requires a different test procedure.

Instructions

V-6 Sensor Test

    1

    Set the digital volt/ohm meter to read a/c volts. Push the meter leads into the back of the electrical connector to make contact with the wires inside. Probe the dark green wire on the connector with the red meter lead (positive), and the black wire with the black (negative) meter lead.

    2

    Turn the ignition key on, but do not start start the engine. Turn the engine crankshaft clockwise, using a breaker bar and socket on the crankshaft bolt in the center of the crankshaft pulley.

    3

    Observe the voltage displayed on the meter. The voltage should vary between 0 volts and 5 volts as the engine is turned over. Replace the sensor if voltage is a steady 5 volts. Have the on-board computer checked if no voltage is found at the sensor.

V-8 Sensor Test

    4

    Unplug the wiring harness electrical connector from the sensor. Test for battery voltage at the electrical connector. With the ignition key on and the engine off, the voltage at the connector should be around 12.5 volts (battery voltage). Check for a burned fuse in the under-hood fuse block if no voltage is supplied to the connector.

    5

    Remove the sensor retaining bolt from the front of the driver-side cylinder head, using a 10-mm wrench. Twist the sensor back and forth as you pull it out of the cylinder head. Touch meter leads to the terminals in the sensor.

    6

    Pass a screwdriver close to the end of the sensor and observe the voltage. Replace if there is no pulsing voltage displayed on the meter, as the screwdriver passes the end of the sensor.

Catalytic Converter & Loss of Power

Catalytic Converter & Loss of Power

Catalytic converters contain one or more ceramic blocks with thousands of tiny holes called micro-ducts. If these ducts become damaged, they can collapse and impede exhaust flow, and cause a reduction in horsepower.

Restriction and Power

    Your engine produces exhaust gases when it burns air and fuel inside of its combustion chambers. If these gases get stuck inside the cylinders, they'll take up space that should be occupied by incoming air and fuel. This air/fuel displacement causes the engine to act smaller than it actually is, resulting in a loss of power and fuel efficiency.

Stock Converters

    All catalytic converters create a certain amount of restriction (back-pressure) in the exhaust stream. How much back-pressure they cause is a function of the size and number of micro-ducts. Larger and more numerous ducts impede flow less than smaller and fewer ducts.

Damaged Converters

    Excess heat inside the converter (usually caused by an excessively rich air/fuel ratio) can crack the ceramic blocks and cause the micro-ducts to collapse. The remaining exhaust must then squeeze through a fewer number of ducts, imparting its thermal load to a smaller area. That heat causes more of the ducts to crack and collapse, which results in a cascade effect of failure known as "converter melt-down," and it can be resolved only by replacing the converter.

How to Troubleshoot a Chevy TH350 Transmission

Chevrolet first produced the TH350 transmission for the 1969 model year. The fully automatic transmission was equipped with three forward gears and one reverse gear. Although the design of the TH350 is fairly primitive compared to today's computer-controlled transmissions, major disassembly should be left to a professional. There are, however, a number of fairly straightforward problems that can be corrected without the assistance of a professional.

Instructions

    1

    Start the engine and allow it to warm.

    2

    Withdraw the transmission's dipstick and inspect the fluid on the dipstick for water contamination. Water will appear as bubbles. Drain the transmission fluid into a container by removing the drain bolt at the bottom of the transmission with a wrench. Also remove the drain bolt at the bottom of the torque converter. The torque converter is between the transmission and the engine and must be accessed from underneath the vehicle. Pour 12 quarts of General Motors Dexron transmission fluid into the dipstick tube.

    3

    Withdraw the transmission's dipstick. Wipe the fluid off of the dipstick with a clean rag, then reinsert the dipstick into the transmission. Withdraw the dipstick again and read the fluid level. The level must be between "Full" and "Add," as indicated on the dipstick. If the fluid level is below "Add," pour General Motors Dexron transmission fluid into the dipstick tube.

    4

    Inspect the transmission's vacuum line for cracks. If the hose is cracked, a vacuum leak will result and cause the transmission to shift erratically.

    5

    Adjust the shift linkage. The shift linkage connects the shift lever to a bracket on the driver's side of the transmission. The design of the shift linkage varies greatly depending on the vehicle, but the basic principal is the same. The linkage is secured to the transmission bracket with a bolt or clip. Remove the fastener with a wrench or with pliers to release the linkage from the transmission's bracket, then move the shift lever to the park position. Rotate the transmission's bracket to its extreme clockwise direction, then reattach the linage to the bracket.

    6

    Replace the control valve body gasket, as it may be leaking. A leaking valve body gasket is an often-overlooked cause of erratic shifting. Unfortunately, the gasket cannot be inspected for leaks without removing it and, once removed, the gasket must be replaced. Allow the engine to cool, then drain the transmission and remove the transmission's oil pan with a wrench to expose the filter. Remove the filter's retaining bolts and lower the filter out of the transmission to expose the valve body. The filter bolts to the bottom of the valve body. Remove the valve body's bolts with a wrench and lower the valve body out of the transmission. Replace the gasket located on top of the valve body with a new gasket. Do not apply gasket sealant to the valve body gasket. Tighten the valve body into the transmission. Tighten the filter onto the valve body. Apply gasket sealant to a new pan gasket and bolt the gasket to the transmission. Fill the transmission with fluid.

    7

    Replace the transmission's filter if the transmission still shifts erratically. Allow the engine to cool, then drain the transmission and remove the transmission's oil pan with a wrench to expose the filter. Remove the filter's retaining bolts and lower the filter out of the transmission. Position the new filter against the transmission and tighten the filter's bolts. Apply gasket sealant to a new pan gasket and bolt the gasket to the transmission. Fill the transmission with General Motors Dexron transmission fluid.

How to Troubleshoot a 1987 Chrysler Fifth Avenue

The 1987 Chrysler Fifth Avenue sedan was designed as a luxury model car. It had a 318-cubic-inch V-8 engine and other optional features, such as air conditioning, tilt steering wheel and automatic climate control. As the owner of this aging vehicle, you may experience occasional problems with it. Troubleshooting them yourself can help head off bigger issues and thereby avoid the cost of expensive repairs. It also eliminates the need to take your car to the mechanic to perform these simple and basic tests that you can do.

Instructions

    1

    Check the tire inflation pressure with a tire gauge if you notice that your vehicle is riding or steering unevenly. Failing to maintain the correct pressure can result in irregular wear which causes an uneven ride. The recommended pressure for standard stock tires on the 1987 Fifth Avenue is 32 psi.

    2

    Check the amount of brake fluid in the master cylinder reservoir if your brakes feel "spongy" when depressed. Raise the hood and locate the reservoir near the engine. Remove the cap and check the amount of brake fluid. Depending on the type of reservoir, do this by either using a small dip stick attached to the cap or looking at the fill line on the reservoir. If the fluid level is low, add brake fluid as specified in the owner's manual.

    3

    Check and recharge the battery if you are unable to start the vehicle. Turn the key in the ignition switch one click and turn on the windshield wipers. If they do not move or drag slowly across, you may need to recharge your battery. Give it a boost using a second car. Start the engine of the other car and attach the positive and negative clips of a set of jumper cables to its matching battery terminals. Connect the other positive and negative clips to the matching battery posts on the Fifth Avenue. Start the Fifth Avenue and disconnect the jumper cables starting with the negative clip. Allow the car to continue to run for at least 15 minutes to charge the battery.

What Is Code P1105 on My Ford E-350?

What Is Code P1105 on My Ford E-350?

As part of Ford's E-Series, the E-350 is a full-size van available with an automatic engine. Utilizing diagnostic trouble codes allows you or your mechanic to troubleshoot potential problems your E-350 may have. In particular, code P1105 allows you to diagnose possible engine computer issues.

Code P1105

    A Ford code P1105 translates to "Manifold Absolute Pressure/Baro Solenoid Circuit Malfunction." The MAP sensor, which measures the pressure of the intake manifold, allows the engine's computer to adjust ignition timing. Ford technical service bulletins (TSBs) report that an E-Series code P1105 primarily indicates ignition module failure due to a failing MAP sensor.

Symptoms

    Both ignition module and MAP sensor failure are indicated by poor engine performance, poor fuel economy, power loss and stalling. Intermittent power loss may result in complete power loss if the issue is not addressed.

Solution

    A mechanic must decipher if the MAP sensor or the ignition module is the primary problem. It is likely that a faulty MAP sensor has caused the ignition module to fail, which would require both to be replaced. Aside from the MAP sensor itself, its vacuums and electrical connections may require replacement.

Senin, 18 Mei 2009

How to Check the ECU Code Flashes

Vehicles produced in 1996 and later are equipped with OBD-II, or On-Board Diagnostics II, a computer system that monitors the engine and other parts of the vehicle. When a vehicles Check engine light illuminates, it can be caused by a variety of problems. Whether the issue is intermittent or more serious, the vehicles computer keeps a record through the use of codes. It is possible to obtain the code by connecting an OBD-II scanner to the vehicles engine control unit, or ECU. Once the code is obtained, you can find out the specific problem with the vehicle.

Instructions

    1

    Turn the car's ignition to the "Off" position.

    2

    Find the vehicles ECU connector. All vehicles equipped with OBD-II have a connector in the vehicles passenger compartment. Check under the dashboard and near the ashtray. The ECU port must be within three feet of the driver and not require any tools to access.

    3

    Connect the ODB-II scanner to the ECU port. The port has 16 pins, with eight pins on top and eight on the bottom; the connector is in the shape of a trapezoid.

    4

    Insert the key into the ignition and turn the key to the On position. Do not start the car.

    5

    Turn on the OBD-II scanner.

    6

    Press the Read button on the scanner.

    7

    Follow the instructions on the scanners LCD screen. Each manufacturers directions will be slightly different, so read the owners manual.

    8

    Write down the codes displayed on the scanners screen.

    9

    Look up the codes to find the specific problem (see Resources).

How to Troubleshoot a 1987 Volkswagen Cabriolet

How to Troubleshoot a 1987 Volkswagen Cabriolet

The Volkswagen Cabriolet was manufactured from 1980 through 2002. The Cabriolet was the convertible version of the original Volkswagen Rabbit. It became a model unto its own when Volkswagen discontinued the Rabbit. Like any car, there are electrical and mechanical systems that can break down over time, including the retractable roof. When this happens, you can troubleshoot the problem at home before you take your car into the garage.

Instructions

    1

    Listen for noises coming from your 1987 Volkswagen Cabriolet when driving it. The roof on a hard top car offers a lot structural support. Convertibles like the Cabriolet require locks to hold the roof in place. If the locks are starting to fail or crack, you may hear rattling or creaking from the roof section of the car.

    2

    Check the fuse box on your 1987 Volkswagen Cabriolet for blown fuses if any of the electrical systems are not working on your car. Items like the radio, heater fan motor and other electrical systems require good fuses for them to work properly.

    3

    Remove and inspect the fuel and air filters if the engine is running rough. Internal combustion engines require the proper mix of air and fuel to run properly. If the filters are gummed up or dirty, replace them with new ones. If the engine continues to run rough, remove the spark plug wires and the spark plugs from your 1987 Cabriolet. Replace the spark plugs with new ones and reconnect the spark plug wires.

Professional Auto Mechanics Diagnostic Tools

Professional Auto Mechanics Diagnostic Tools

When a car shows a warning light or develops an unusual noise, a mechanic uses professional auto mechanics diagnostic tools to pinpoint the trouble. Three different types of such professional tools are available: information tools, scanning tools and other hand-held tools.

Information Tools

    Today's cars have a diagnostic system called On-Board Diagnostics II or OBD II, which keeps track of the workings of the engine systems and the transmission. When this system generates a Diagnostic Trouble Code or DTC, the mechanic can look up the code definition from the manufacturer of the car, or can find it at specific websites on the Net. Another information tool is the diagnostic flow chart, which gives the mechanic a step-by-step guidance for testing issues difficult to diagnose. Diagnostic flow charts give the information the mechanic needs to find the problem by eliminating what works. Factory service bulleting can also be helpful to the mechanic in pinpointing trouble in a vehicle. They identify potential safety hazards and give the information necessary to fix them. Such bulletins make the mechanic aware of manufacturing defects and part failures and can pinpoint hard-to-repair issues for certain cars.

Scanning Tools

    All newer cars have a special plug for On Board Diagnostics II, or OBD-II under the dashboard, where the mechanic can interface with the vehicle to check emissions and other critical car systems. Trouble code readers are scanners that interface with the OBD-II plug and read the manufacturer's Diagnostic Trouble Codes. These readers are often tuned for specific makes of cars and trucks. Some of them come with software. After scanning the problem, the scanner plugs into a computer to let the mechanic know exactly what the problem is, a possible cause, repair instructions and the approximate cost. Other diagnostic scanning tools check emission problems only, or focus specifically on brake functioning. Some are available with printer capabilities.

Other Diagnostic Tools

    Common professional auto mechanics tools include vacuum test kits that test the vacuum the engine generates when it's running and pinpoints any blocking or breaks in the vacuum line. A vacuum test kit also comes with a brake-system bleed attachment, which can show whether brake fluid needs to be refilled. Fuel pressure gauges help the mechanic find any problems with the pressure in the fuel injection system. A simple test light is also a useful diagnostic tool, since it can show any problems in a vehicle's electrical circuits. These lights are excellent for testing wires, fuses and for checking the surface charge of a vehicle's batteries. For computer-related circuits, however, a mechanic will use a voltmeter or multi-meter. An IR or infrared meter uses an infrared beam to check the temperature and can show engine cylinder misfires, cooling system and air conditioning problems and also works to show exhaust system and heater malfunctions. Another diagnostic tool is an air pressure gauge to check the tire pressure.

Minggu, 17 Mei 2009

Reason That the Car's Blower Fan Does Not Work

Reason That the Car's Blower Fan Does Not Work

The blower fan on a car moves air from the air conditioning and heating units located under the hood of the car to the interior of the vehicle to heat or cool the air inside. When the blower fan is not working, it is quite an irritant as the air in the car is no longer kept at a comfortable temperature.

Blown Fuse

    Usually the first thing to inspect when the blower fan stops working is the fuses to see if any are blown. Locate the 10A cluster fuse or the 25A HVAC fuse in your car manual, and examine them to determine if they need replacing. The car owner's manual will tell you where to find the fuses that are connected to the heat and/or air conditioning. On the interior fuse panel of the car, a 30 amp fuse is labeled "Heater" or "HVAC."

Bad Blower Motor

    If the fan only works on setting number 3 or 4, or just on the highest setting, it is most likely that your blower motor is failing and is about to die. Use a voltmeter to test the amount of voltage at the blower motor connector with your ignition on and AC running. If it reads 12V, the motor needs replacing.

Automatic Climate Control System

    Another thing that causes the blower fan to malfunction is the Automatic Climate Control System (ACCS). If the ACCS's settings are off, it may cause the fan to stop working. If it is the climate control on the car, typically it is a bad thermostat or electrical circuit that is the culprit.

How to Troubleshoot a Marine Shifter Cable

How to Troubleshoot a Marine Shifter Cable

Shifter cables on marine craft provide the function of selecting the transmission gears that provide forward movement, neutral and reverse. The cable connects to a shifting lever at the cockpit location and runs along the rail or bilge gutter to connect at the linkage on the upper case of the motor. Shifting cables, although adjustable, can suffer some problems that impede or stop the shifting process. A boat owner should familiarize himself on the theory and operation of the shifter cable and know how to troubleshoot any problems that may arise.

Instructions

    1

    Install a muff flush device on your lower unit and connect it to a garden hose, if you have your boat on a trailer. If your boat is moored or docked in the water, leave it there for the cable shifting test. Make your first visual inspection of the cable condition. Look for any cracks or gouges in the outer sheath material. Any openings in the sheath will allow water inside to rust the cable and freeze it up. Replace any cable that has visible damage. Run your finger along its underside, from the shifter control box to the engine case, feeling for wrinkles.

    2

    Look for bends or 90-degree angles in the cable along its path. Any kinks will keep the cable from free movement and shifting properly. Check the transom cable mount for loose bracket bolts and the security of the fastening mechanism that connects the cable end to the shifting cams on the engine. If the cable is secured to the engine case by a cotter pin or nut, make sure they are installed correctly and tight. Tighten the flange nut that holds the sheath against the mounting bracket with an end wrench.

    3

    Use a screwdriver to remove the shifter box housing. Check the shifter box mounting bolts which hold the mechanism to the bulkhead and tighten them with a socket and wrench or screwdriver. Ensure that the cable connected to the shifter lever is secure and tight. There can be no excess play in the transom bracket or inside the shifter box which allows physical movement.

    4

    Start the engine and let it warm up in neutral. Cast off any lines. Shift the lever into forward gear and let the craft move forward. If the motor stalls after shifting into the forward gear repeatedly, inspect the small micro-switch on the transom bracket. The switch is called an interrupter switch, or "kill" switch. The switch can not be bent or disabled, because it assists in changing the pattern from forward and reverse to neutral. If the shift cable is stiff or binds for any reason, the switch will sense the tension and "over-kill," stalling the engine.

    5

    Shift to neutral to see if the engine remains in gear. If the shift lever heavily resists, and you must use great force to position it in neutral, it indicates the cable has bound in the sheath, and the interrupter switch has failed completely. This results in a shifting lever that goes from forward or reverse gear, bypasses neutral completely and slams into the opposite gear. Consult your service manual for the proper switch replacement design and replace it. Any heavy tension required to move the shift lever into any gear, indicates a bound or dry cable -- replace the cable.

My Chevy Pickup Won't Start

My Chevy Pickup Won't Start

Several pickup truck are manufactured under the Chevrolet brand, which is owned and operated by General Motors. The Avalanche is the newest Chevy pickup that was added to the existing makes, the Colorado and the Silverado. The Silverado comes in several models, including the 1500, 2500HD, 3500HD, and the Hybrid. Each of these vehicles can have problems starting at times. Before calling in a professional, you can check some mechanisms in the car to save time and money.

Instructions

    1

    Attempt to turn your key in the ignition of your pickup. If it will not turn, the steering wheel locking system may be a problem. Turn the wheel to the left and right until you hear a click indicating that the steering wheel is in the correct position. Turn the key again.

    2

    Check the battery of your Chevy pickup by turning the key in the ignition to the "Accessories" position. The electrical components of the vehicle should work without the engine running. Turn on the interior lights or the headlights. If they do not come on, the battery is drained or dead. It might have to be replaced but it could just need a jump start or to be charged.

    3

    Look at the fuel gauge while the key is in the "Accessories" position. If the gauge reads low or you are unsure how much fuel is in the vehicle, add a gallon of the appropriate fuel to the tank.

    4

    Turn the key to the "Start" position. Listen for sounds that might indicate a problem. If the engine starts and sputters out or stops, the fueling system, including the fuel tank, fuel pump or fuel filter, may have malfunctioned. Clicking noises could indicate a problem with the starter and no sound at all could indicate a problem with the ignition switch.

    5

    Pull the lever that opens the hood of your Chevy pickup. Locate the coolant reservoir and the dipsticks for the oil and transmission fluid. Check each fluid level and be sure that it is above the minimum line, as low fluid levels can cause damage to the engine.

    6

    Tow or have your Chevy towed to a garage or dealership where further diagnostic testing and repairs can be done.

Sabtu, 16 Mei 2009

How to Troubleshoot a Chevrolet Fuel System

How to Troubleshoot a Chevrolet Fuel System

A Chevrolet's fuel system, along with the emissions and the engine, form the vehicle's overall powertrain. The three systems are connected and are, to a certain extent, related. Troubleshooting any part of these three systems can be difficult, especially if you do not know exactly what problems to look for. Your Chevrolet is equipped with something that will both save you time and make the process a little less difficult. If you access the Chevrolet's on-board diagnostic system, you can retrieve a list of active problems within the powertrain. This, however, would only be the beginning of the troubleshooting process.

Instructions

    1

    Open your Chevrolet's driver side door and take a seat. Slide your key into the Chevrolet's ignition, start the engine and watch the vehicle's dashboard panel. All the lights will turn off temporarily as you engage the starter. Look for any lights remaining active, but take note of the check engine light. If it is lit, then there are trouble codes within the system.

    2

    Turn the Chevrolet's key to off, but leave the key in the ignition. Look under the dashboard and above the floor. You are looking for the Chevrolet's data link connector. Its exact location depends on the model and year of your Chevy. It is, however, usually located either directly below the steering column or some place between the gas pedal and the left kick panel. It will be uncovered.

    3

    Connect your OBD-II scanner to the Chevrolet's DLC outlet. The scanner will come with a diagnostic cable. Connect the cable to the scanner, and then plug the cable into the DLC outlet.

    4

    Switch your OBD-II scanner on. Return to the key you left in the ignition and switch it to the on position. You may be using a scanner that also needs an active engine. If so, start the engine.

    5

    Look at the scanner's display read out, once the device and the Chevy's OBD-II system have interfaced. You may need to enter a code-retrieving command, if your particular device was not sold with auto-retrieval programmed into it. Consult your device's manual and follow the instructions offered. OBD-II devices differ by brand, so the process is not the same for all devices.

    6

    Copy all the active codes onto a separate sheet of paper. Then, unplug the scanner. Turn the Chevrolet's engine and electrical system off. Remove the key from the ignition.

    7

    Look up definitions for each of the codes on your list. You will need at least two separate resources for this. Your device's handbook should have all the generic codes standard to all OBD-II compliant vehicles. You will also, however, need to locate General Motors' supplemental OBD-II set. This will neither be in your device's manual nor the your Chevy's owner's manual. You can locate these codes online for free.

    8

    Read through all the definitions. Place a check mark next to any code related to fuel or the fueling system. For example, Codes P0002 and P0003 both deal with specific ignition cylinders.

    9

    Open the Chevrolet's hood and begin troubleshooting, using your code list as a resource. Go through all the check-marked codes first. Troubleshoot not only the exact component named in the coding definition, but the whole system connected to that part. For example, if you are troubleshooting P0002 and P0003, look not only at the specific ignition cylinders, but all of the cylinders and the wiring connecting them.

Kamis, 14 Mei 2009

What Causes a Transmission to Slip in a Car?

What Causes a Transmission to Slip in a Car?

An automotive transmission, located underneath a vehicle, allows you to shift from gear to gear. Unfortunately, transmissions tend to break down over time. One common transmission problem involves slipping out of gear. Causes of this condition include improper transmission levels, weak transmission belts and unsound gears.

Weak Transmission Belt

    Transmission belts connect the transmission gears. If the belts start chafing or become overextended, they will cause the transmission to slip. This condition can cause major transmission problems if you don't replace inadequate belts over a long period. Check your transmission belts during routine maintenance inspections to prevent this problem.

Weak Transmission Gears

    Transmission gears control how the transmission shifts under different tensions. If these gears become weak or worn out, the transmission will begin to shift improperly, resulting in slippage.

Improper Transmission Fluid Levels

    Transmission fluid keeps the transmissions gears lubricated. The torque converter box properly pressurizes and moves the fluid throughout the transmission. When the system contains too much or too little transmission fluid, the gears will not work correctly and will cause the transmission to slip.

How to Troubleshoot a 289 Engine

The Ford 289 engine was among Ford's more popular small block engines of the 1960s until it was replaced by the 302 in 1968. The 289 was equipped in a number of vehicles, but is probably most closely associated with the Mustang and the Falcon. The 289 featured a fairly simple design, retaining almost all of the features of its predecessor, the 260. Although a seemingly endless number of causes can be traced to a particular symptom, the cause of the vast majority of problems associated with the engine can be traced without disassembling the engine.

Instructions

Engine Does Not Start

    1

    Inspect the tips of the battery cables for corrosion. Battery corrosion typically appears as a white chalky powder and can prevent the battery current from reaching the cables. Clean the battery terminals and the tips of the cables with a battery terminal brush if corrosion is present while wearing heavy gloves and safety goggles.

    2

    Attach a voltmeter to the battery. The meter should indicate that the battery holds a charge of between 12 and 14 volts. If the battery does not hold between 12 and 14 volts, charge the battery with jumper cables attached to a working battery. Replace the battery if it does not hold a charge.

    3

    Ensure that the battery cables are secure with a wrench. The negative cable leads from the battery to the side of the engine block. The positive cable attaches to the starter solenoid. A cable on the opposite side of the solenoid attaches to the starter motor.

    4

    Attach one end of a jumper cable to the positive battery terminal. Quickly touch the opposite end of the jumper cable to the threaded rod on the side of the starter solenoid that connects the solenoid to the starter motor. Replace the starter solenoid if the starter motor does not turn. If the starter motor turns but the engine does not, replace the starter motor.

Engine Idles Unevenly and Misfires

    5

    Replace the fuel filter, as it may be preventing a sufficient supply of gasoline from reaching the engine. The fuel filter is the metal canister located on the front of the carburetor. The fuel line attaches to the back of the filter. Unscrew the filter by turning its integral nut in a counterclockwise direction with a wrench.

    6

    Determine whether the valves are adjusted properly. Two versions of the 289 were produced, the standard 289 and the very rare high-performance 289. The standard 289 was equipped with hydraulic valve lifters, while the high-performance 289 was fitted with solid valve lifters. The standard 289's lifters must be adjusted with the engine running. Remove the valve covers and start the engine. Turn one rocker arm nut in a counterclockwise direction with a wrench until a taping sound is produced, then tighten the nut only until the sound stops. Finally, tighten the nut an additional 3/4 of a turn. The high-performance 289's lifters must be adjusted with a feeler gauge and with the engine turned off. Remove the valve covers and measure the distance between the top of one valve and that valve's rocker arm with the feeler gauge. The distance must be 0.018 inches. Loosen or tighten the rocker arm nut to adjust the distance.

    7

    Remove the spark plugs from the engine with a spark plug wrench. Insert a compression gauge into any spark plug opening on the cylinder head. Depress the gas pedal to the floor and turn the engine with the ignition key for a few second. Record the reading of the compression gauge and repeat the process for the remaining spark plug openings. Compare the results. If the reading is significantly lower on two adjacent cylinders than on the remaining cylinders, the head gasket may be defective. If only one reading is significantly lower, that cylinder may have burned out valves or worn piston rings.

Excessive Oil Consumption

    8

    Start the engine and allow it to warm up. Observe whether a blue-colored smoke emanates from the exhaust pipe while the engine idles. Blue-colored smoke is an indication that the piston rings have failed. Oil is passing over the rings and burning with the fuel in the combustion chamber.

    9

    Start the engine and allow it to warm up. Pull the breather cap off of the top of each valve cover. Observe whether smoke is escaping from the breather cap openings on the valve covers. If smoke is present, the valve guides and/or the valve stem seals are likely worn.

    10

    Start the engine and allow it to warm, then turn the engine off. Inspect the bottom of the engine for an oil leak. Pay particular attention to the top of the oil pan and the bottom of the timing chain cover, which indicates a blown gasket. If a leak is present at the back of the engine, where the oil pan meets the engine, the rear main oil seal may be defective. Finally, check for leaks around the oil filter, which indicated that the filter may be loose. Take care not to over tighten the filter, as it should only be hand-tight.

Rabu, 13 Mei 2009

Troubleshooting a Car Audio Sub Amp

Troubleshooting a Car Audio Sub Amp

A car amp and even the entire audio system are put under some unusual stresses. The car can go through extreme temperature changes, and it distributes all the bumps and turns of the road straight to the audio components. Given this harsh environment, it is common to have some problems with your car's audio subwoofer amplifier that may need some troubleshooting. Learn how to do this and hopefully find a quick and easy fix to your car audio woes.

Instructions

    1

    Inspect the amplifier and all its connecting cables. Most amps have a light that indicates the amp is receiving power. Verify that the light turns on when the rest of the car audio system is powered on. If not, there is likely a problem with the power or ground cable. Inspect all the inputs, including the RCA cables, the remote wire and the speaker wire. Ensure that the wires are fully secured to the amp and no exposed metal is visible which could lead to shorting out the system.

    2

    Look for any physical damage to the amp or any signs of smoke coming out of the amp. An amp can be damaged due to physical harm or overheating. Signs of this should be obvious, such as chips of metal coming off the amp, broken inputs or discoloration of the metal. This damage may indicate that the amp is beyond repair.

    3

    Check the levels on the amp. The gain level controls the output of the amp and may inadvertently be turned down. Turn the gain up to the point where you are hearing music again. Crossover levels and high or low pass filters may be set to the wrong setting. Consult the owner's manual for your amplifier to make sure you know where they should be set as they vary for every amp.

    4

    Check the ground wire to see if it has become dislodged. The ground wire attaches to the metal chassis of the car, and the amp will not function without it. In addition, the connection point is often hidden and can sometimes become detached without the operator noting that anything is wrong. Reattach the wire with a firm connection to a metal part of the car's chassis.

Starting Problems in a 1998 Jeep Cherokee

Starting Problems in a 1998 Jeep Cherokee

Jeep has produced the Cherokee SUV since 1974, with major redesigns occurring in 1984, 1997, and 2002. In 2008 the Cherokee was re-branded as a Jeep Liberty. Early models were carbureted and in 1986 Jeep switched to fuel injection in all its Cherokee engines. The original model had four different engine choices, from an inline 6 cylinder to a massive 401 c.i. V8. The second generation had seven possible engine choices including two diesels. The third generation had only five engine choices as did generations four and five, albeit with different engines each time.

Instructions

Engine Will Not Turn Over

    1

    Check the battery connections first. Disconnect the battery cables with a wrench and clean the posts and connectors with a wire brush. Always use a socket or box wrench as an open ended wrench will wear the corners off the bolt on the cable connectors and it will become impossible to fully tighten them.

    2

    Switch on the wipers or headlights with the ignition key in the "On" position. If nothing works, the battery is likely discharged and requires charging or replacement.

    3

    Switch ignition key to the "On" position and adjust the transmission shifter to ensure it is in the "Park" or "Neutral" position. This only applies to automatic transmissions.

    4

    Lift the vehicle up with a jack and rest it on jack stands. Inspect the electrical connection between the battery and starter motor. Replace the main positive cable from the battery if it is damaged and clean and tighten the connection at the starter solenoid. The starter motor is located on the lower side of the bell housing just behind the engine.

    5

    Remove the starter motor and electrical connections with a wrench and inspect it to see if the pinion gear has become jammed in the flywheel. In some cases you may be able to unjam the pinion and get it working again but it likely should be replaced before it gets jammed again. Remove the starter and solenoid and have a mechanic test that it is functioning properly.

Engine Turns Over But Will Not Start

    6

    Check the fuel tank for fuel. If there is fuel then it may not be reaching the engine. Start by checking the fuel filter. There are over 25 different engines in the Cherokee, but most will either be at the carburetor in older engines, or inline in fuel injected engines. Disconnect the filter with wrenches and inspect for water or dirt. Most filters cannot be cleaned and reinstalled so be prepared to install a new filter. Fuel injected systems must be depressurized before removing the filter.

    7

    Test the fuel pump. In most cases this means disconnecting the fuel line at the carburetor or throttle body and cranking the engine while holding a fuel line into a container. The process is more complicated with fuel injected systems but the goal is the same, to see if fuel comes out when the engine turns over. If no fuel comes out then the fuel pump either needs replacing or its electrical connections are loose or corroded or there is damage to the wires.

    8

    Inspect the carburetor, if your engine has one. Remove the wing nut on the air filter and lift the air filter assembly from the top of the carburetor. Check if the choke is stuck, the carburetor jets clogged, or the float has stuck. Any of these problems may require analysis and repair by a trained mechanic.

    9

    Remove several spark plugs with a wrench and inspect for spacing and buildup of carbon or oil deposits. Inspect the spark plug cables for damage and that they are securely connected at the plug and distributor. Replace any faulty cables. On older models check that the distributor cap is tight and there is not water inside it. Remove the timing chain cover with a wrench and inspect the chain for damage or breakage.

Selasa, 12 Mei 2009

How to Troubleshoot a VTEC Cam Solenoid

The VTEC solenoid in your vehicle uses a connection to an engine control unit, or ECU, to convert electrical energy into mechanical energy. A disruption in this connection may result in signs of a faulty solenoid. Before you replace your solenoid, ensure a proper connection between the solenoid and ECU connectors. If you fail to connect the solenoid wires to their corresponding connectors, the solenoid will not work properly.

Instructions

    1

    Observe signs of an improperly connected VTEC cam solenoid. A car may perform sluggish, like it's not getting enough power, if there's a disruption in the connection between the VTEC solenoid and ECU.

    2

    Ensure a proper connection between the VTEC solenoid and ECU "A." ECU "A" is located to the left of ECU "B" and ECU "C." Two solenoid wires should connect to ECU "A."

    3

    Verify correct wiring between the VTEC solenoid and ECU "A." The yellow solenoid wire must connect to connector "A17" on ECU "A." The red solenoid wire must connect to connector "A8" on ECU "A."

    4

    Drive the vehicle. If shifts do not occur at proper speeds, or the vehicle continues to perform in a sluggish manner, this may be an indication of a problem with the solenoid.

    5

    Bring the vehicle to a mechanic for diagnostic testing. The mechanic will test solenoid valves and their electrical circuitry, as well as terminal voltage and gear position. These tests can help the mechanic identify and resolve problems related to a sticking solenoid, an open circuit to the solenoid or a faulty solenoid.

Senin, 11 Mei 2009

How to Cancel Dodge Truck Diagnostic Codes

How to Cancel Dodge Truck Diagnostic Codes

No matter the type of scanner you are using, the process of canceling out and clearing diagnostic codes on a truck is relatively simple. Whether you are trying to get rid of On-Board Diagnostic codes or ABS brake service light codes, the process is fundamentally the same. All three code scanners hook up to the same data link connection port, and this diagnostic computer outlet is usually located under the truck's dashbaord and steering column. Nulling out the code takes only a few minutes.

Instructions

    1

    Hook the diagnostic scanner up to the data link connection beneath the stearing wheel. This outlet is usually made of hard black plastic, and it features 16 pin receptors. Each "slot" is dedicated to a different purpose. The location of your truck's data link connection and purpose of each receptor may very by make and model. See the link in Resources to look up your specific truck.

    2

    Turn the scanner on.

    3

    Place your key in the truck's ignition and turn it on. If simply turning on the electrical system does not establish a connection with the diagnostic system, start the truck's engine.

    4

    Wait for the trouble code to appear on the screen. This will only take a few seconds.

    5

    Locate and press the "Clear" button. On some scanners, it might be marked "Erase" or by some other similar word. Consult the manual specific to your hardware for exact instructions. This will clear the trouble code from the specific diagnostic system you have. Unless you have an expensive diagnostic computer, one type of scanner cannot wipe the codes from another system. An ABS scanner, for example, cannot clear OBD trouble codes.

    6

    Turn the truck off and unhook the diagnostic scanner.

Minggu, 10 Mei 2009

What Are the Causes of Front End Whine at Road Speed in a 2002 KIA Sedona?

Kia introduced its Sedona minivan in 2002. This minivan came in two trim levels: EX and LX. Both trim levels came fitted with a 195-horsepower, 3.5-liter V-6. Over time, the Sedona can develop a whining or humming noise from the front end. This sound can be caused by many things, some of which are minor problem and others which are far more serious.

Tires

    Tires wear out over time and sometimes they wear out in uneven patterns. One of these patterns is when the tread becomes choppy. This choppiness can be caused by a few things, but it is typically due to poor alignment or lack of tire rotation. The choppiness causes a humming or whining sound from the front end. The easiest way to determine if this is your problem is to rotate the tires front to rear. If the noise moves to the rear, then you know the tires are the problem.

Wheel Bearings

    The wheel bearings on the front end are what allow the front wheels to rotate freely. Over time, these bearings can lose their lubricating grease or become contaminated. When this happens, the bearings will begin to make a whining or grinding sound from the front end. An easy way to check if the front bearings are the problem is to listen for an increase in sound when turning the vehicle in one direction. While the bearings are not necessarily easy to replace, this is not a major repair.

Brakes

    Brake calipers use a square-cut O-ring inside the caliper to pull the caliper back when the brake pedal is released. As the vehicle ages, the caliper may not retract fully and allow the brake pads to lightly rub the rotors. This rubbing can create a whining or humming sound from the front end. An easy way to check this is to touch the front rims after driving. If one of the rims is significantly hotter that the other, chances are the caliper is sticking.

Drive Axles

    The 2002 Sedona is a front-wheel drive minivan and has a front drive axle on both sides of the vehicle. These axles have grease inside of them to keep the moving parts well-lubricated. Over time, the rubber boots holding the grease can crack, allowing the grease to seep out. The lack of grease can damage the axle's moving parts causing a faint whining sound from the front end. The best way to diagnose this is to raise the front of the van and inspect the rubber boots on the axles.

Transmission

    This is the worst place to have a whining sound from. The transmission has a distinct sound that comes directly from the engine compartment. The transmission relies on periodic oil changes to keep the fluid fresh and clean. Over time, old fluid may lose its lubricating properties, causing internal transmission damage. This damage sometimes results in a whining sound from the front of the vehicle. The best way to check for transmission damage is to pull the transmission's dipstick and check the fluid for a few things: metallic debris, nearly black in color, stickiness or a burnt smell. If any of these conditions exist, internal transmission damage exists and an expensive transmission overhaul is typically required.

How to Scan Codes on a 1997 Jeep Cherokee

How to Scan Codes on a 1997 Jeep Cherokee

Scanning the OBDII codes in a 1997 Jeep Cherokee can take the guesswork out of the repairs that the codes indicate are needed. OBD is an abbreviation for "On Board Diagnostics," and vehicles after 1995 were switched from OBDI to OBDII. The diagnostic codes in the Cherokee come from the engine as well as the transmission. The process of scanning the vehicle takes no longer than five minutes. The tool needed for this job can be purchased at an auto parts store.

Instructions

    1

    Sit in the driver's seat of the vehicle. Insert the OBDII scan tool into the port. The port for the OBDII scan tool is located directly underneath the dash, below the steering wheel.

    2

    Turn the key to the "accessories" position. This is the position where all the dash lights come on, but the car does not start.

    3

    Turn the OBDII scan tool on. Press the "Read" button on the scanner, or select the "Read Codes" option if you have a digital scanner.

    4

    Write the codes down that the scanner provides you from your vehicle. Write down any additional information that the scanner gives you as well, such as a brief description of the location and problem.

Sabtu, 09 Mei 2009

Troubleshooting GM Computer Codes

Troubleshooting GM Computer Codes

General Motors vehicles are outfitted with diagnostic computers that monitor a systems within the vehicle encompassing not only the engine, but the electrical system, some functions in the brakes, and network communications. Collectively, this diagnostic system is called "On-Board Diagnostics" and it has been standard across all American makes and models since 1996. Troubleshooting these codes requires a diagnostic scanner, and the retrieval process takes only a few minutes.

Instructions

    1

    Locate the computer outlet called a "Data Link Connection" beneath the GM vehicle's dashboard near the steering column. Plug your OBD-II code reader into this outlet and switch it on. OBD-II code readers operate slightly differently. Some are prefigured to switch themselves on once a connection is made. For the precise steps on how to use your code reader, page through your code reader's handbook.

    2

    Start the GM vehicle's electronics, but if you have a code scanner that requires the engine running, you will also need to crank the GM's engine.

    3

    Press the "Scan" or "Read" button on most code readers to retrieve the codes from the On-Board Diagnostic system. Some code readers skip this step altogether and retrieve code the instant a connection with an ODB-II system is sensed.

    4

    Look at the codes once they are retrieved. The first letter will tell you where the problem is located, generally. The "P" codes cover the power train, and correspond mostly with the engine and fuel system. The "C" codes cover the chassis and electrical system; "B" covers the vehicle's body," and "U" is for networking and communications issues.

    5

    Look at the code's status; it will either be "Trouble" or "Pending." This distinction depends on how frequent the problem crops up. Trouble codes mean the problem has happened often, and this activates a GM vehicle's check engine light. Pending codes have happened less often, but these could also be new malfunctions that could become trouble codes.

    6

    Read your code reader's handbook for a codes description and meaning. Your handbook will not have GM's specialized OBD-II codes. These are unique to the GM family, and you will not be able to locate their definitions in a vehicle owner's manual. They can be found for free online.

    7

    Use the coding descriptions as well as the first letter of each code to locate the precise spots within the GM vehicle that need troubleshooting. For example, P1651 is a powertrain code, so you would look at engine related areas. Since the code description refers to "Fan 1 relay control circuit," you would need to troubleshoot the electrical systems around "Fan 1."

How to Clear OBD-II Codes

How to Clear OBD-II Codes

Onboard Diagnostic (OBD) allows cars to sense a malfunction and categorize it. The OBD-II edition of the system is standard for cars manufactured since 1996. The car's computer senses a problem with the motor and activates the "Check Engine" light on the dash. Anybody with an OBD-II scanner can hook up to the car's computer and read this automated diagnosis. Clearing the code after the repairs is highly important. Not doing so will leave the "Check Engine" light on, even if there is nothing wrong.

Instructions

    1

    Hook an OBD-II scanner to the car's diagnostic port. This outlet is on the driver's side, under the dash and usually near the steering wheel.

    2

    Turn the scanner on.

    3

    Turn the car on.

    4

    Wait for the trouble code to appear on the scanner.

    5

    Press the "Clear" button on the scanner to clear the code.

Jumat, 08 Mei 2009

A Fuse Vs. a Circuit Breaker in a Car

A Fuse Vs. a Circuit Breaker in a Car

Automotive fuses and circuit breakers are both designed to protect an electrical device or wiring from damage. However, these devices provide protection in different ways that are important for car owners to understand when maintaining their cars.

Fuse Operation

    A fuse works by using a thin metal strip that can only handle a specific amount of amperage. The amount of amperage that a fuse is designed to handle is stamped into the fuse body. When this amount is exceeded, the metal strip is overheating causing it to break. The fuse must then be replaced to restore electrical power to the circuit.

Circuit Breaker Operation

    When a circuit breaker experiences an overload, a moveable arm within the breaker is heated causing it to move out of place and break the circuit. When the arm cools, it moves back into place and closes the circuit. Manual reset circuit breakers have a reset button that must be pushed to make the breaker operate.

Causes of Failure

    Fuses and circuit breakers are designed to provide enough amperage to supply the components they protect. When either fails it is a sign of a problem. If you experience repeated failure of a fuse or circuit breaker, inspect the wiring and device for problems.

Kamis, 07 Mei 2009

Reasons for Smoke and Water to Come From the Exhaust Pipe

Reasons for Smoke and Water to Come From the Exhaust Pipe

Cars run on an internal combustion engine, where a flammable liquid is ignited in engine cylinders, pushing pistons and powering the engine. When the piston has been pushed, the smoke generated is thrust out of your car through its exhaust system and finally through the tail pipe. It is not uncommon to see water and smoke coming out of the tail pipe for a variety of reasons.

Condensation

    One cause of water coming out of your tail pipe, especially on early mornings, is simple condensation. Overnight the exhaust system's metal cools down to the ambient temperature. When you start your car, it rapidly becomes much hotter than the air surrounding it. The result is condensation forming around and inside of the exhaust system and tail pipe. This liquid is then pushed out with the exhaust and gives the appearance that your car is leaking water.

Water Vapor

    When the engine turns over quickly, it may expel what appears to be unusual smoke coming out of the tail pipe. This is most likely steam from the exhaust manifold heating up and vaporizing the liquid condensation that can build up in the exhaust system. What you could be seeing is water vapor being expelled from the tail pipe.

Smoke While Running

    Your exhaust system is designed to carry the exhaust, or smoke from combustion that has already been used by the pistons in the engine, out through the tail pipe. While exhaust isn't typically obvious as it's expelled from the car, especially if the vehicle is equipped with a catalytic converter, if the temperature is cooler, the exhaust may just be more apparent. This is the same effect as when you can see your breath when it is cold outside.

White Exhaust at Normal Operating Temperature

    If the exhaust is consistently emitting white smoke when it is not cold outside, and continues or starts after the engine has been running for a while, there could be a problem with your engine's cooling system. To be sure, you should consult a mechanic.

Rabu, 06 Mei 2009

BMW SRS Airbag Scan Tools

BMW SRS Airbag Scan Tools

BMW, founded in 1916, is a German company that specializes in engines, automobiles and motorcycles. A scan tool helps diagnose problems associated with diagnostic trouble codes (DTC). It communicates with an on-board diagnostic (OBD) system. If there is something wrong with an airbag, you'll receive a Supplemental Restraint System (SRS) fault code. To determine the exact cause of the problem, you need a scan tool that can capture the SRS codes. These tools save you from running to the mechanic every time that a warning light comes on.

OBDScan-APEX

    This scanner communicates with all vehicles that have the OBD-II system, which is installed on all vehicles made since 1996. OBD-II systems differ from the previous OBD-I systems, where all codes were manufacturer specific. OBD-II codes are generic, and definitions apply to all types of vehicles, including BMWs. The OBDScan-APEX reads standard DTCs plus air bag and anti-lock brake system (ABS) codes. The tool plugs into the dashboard, and you can view the data on your computer. View data in either log or graphical form. Capture data from your vehicle's engine control unit (ECU). As of 2010, this tool costs $139.99, and the price includes a one-year warranty, free upgrades and unlimited phone and email support.

ABS Reader II

    The ABS Reader II Vivid Color reader by OTC Tool allows you to read both your ABS and airbag system along with all codes associated with your OBD-II system. Read and clear the codes once you fix the problem. The scan tool features a QVGA color display and it connects to your computer via a USB cable, which is included with the kit. This scanner also helps you monitor tire pressure to ensure that you don't over- or under-inflate your tires. This tool is compatible with American, European and Asian vehicles. As of 2010, this product costs between $1,200 and $1,400.

R5/SRS

    This scan tool is specifically designed for BMWs made from 1994 through 2002. It pulls all the fault codes associated with your SRS system and gives you the definition associated with that problem. You can reset the warning light after you correct what's wrong with the airbags. This Peake Research Corp. R5/SRS scan tool comes with a carrying case. It also comes with a code chart, and you can choose from two plug types, depending on what your vehicle uses. As of 2010, this diagnostic scanner costs $129.99.

Selasa, 05 Mei 2009

How to Check the Compression on a 2001 Ford Focus

As the pistons in the engine of your 2001 Ford Focus move up in the cylinder, during the compression stroke, they compress the air/fuel mixture. This causes the mixture to heat up to slightly below the self-ignition temperature of the fuel. Just before the piston reaches top dead center of the stroke the spark plug fires and ignites the fuel. As the engine wears, compression is lost and may misfire if the fuel isn't heated enough during the compression stroke. A compression test will verify the compression of the engine and diagnose low compression.

Instructions

    1

    Start the engine and allow it to idle for a few minutes to warm it up. It isn't necessary for the engine to be at operating temperature, it only needs to be warm. Turn the engine off.

    2

    Remove all four spark plug wires from the spark plugs. Grasp the plug wire boots with the spark plug wire pliers and twist the boot while pulling the wire off the spark plug. The 2001 Ford Focus is a front-wheel drive vehicle with a transverse mounted four cylinder engine. The spark plugs are located on the side of the motor, facing the front of the engine compartment, and are easily accessible.

    3

    Unscrew all four spark plugs using a 5/8-inch spark plug socket, extension, and ratchet. Remove the fuel pump fuse from the auxiliary fuse box located in the engine compartment between the firewall and the air filter housing. In the 2001 Focus the fuel pump fuse is in position number 12 as marked on the fuse box cover. This will prevent fuel from being supplied to the injectors during the test and prevent the possibility for an engine fire.

    4

    Block the throttle open by using a weight, or other suitable object, to fully depress the throttle pedal. Screw the hose from the compression tester into the number one cylinder spark plug hole. In the Focus are numbered from left to right. Plug the compression tester gauge onto the hose.

    5

    Turn the ignition key to the start position and listen to the engine. As the pistons travel up through their compression stroke it will slow during the compression stroke of the cylinder with the compression tester installed causing an audible change in the sound of the engine. Crank the engine six revolutions and observe the pressure shown on the compression tester.

    6

    Repeat the test on the remaining cylinders. If the lowest cylinder pressure is 15% less than the highest cylinder pressure, go to next step. If the cylinders are within 15% of each other the compression is within tolerances.

    7

    Perform a "Wet" compression test on the lowest cylinder. Add a tablespoon of oil into the cylinder with the lowest compression and reinstall the compression tester. Crank the engine for six revolutions and observe the pressure on the gauge. If the pressure increases, more than a few psi, during the wet test the piston rings are worn out. If the pressure remains the same the valves are not sealing properly.

How to Know If an Injector Is Bad?

In a multi-port fuel injection system, each cylinder has its own fuel injector. The fuel injectors need fuel delivered to them at a certain pressure -- commonly 32 to 44 p.s.i., depending on the year, make and model of your vehicle. If the fuel pump is bad, all the injectors will seemingly malfunction, as there won't be enough pressure to keep the engine running properly. If the engine is misfiring, there is most likely a problem with one or more injectors or the injector circuits, if the ignition system is working properly.

Instructions

    1

    Locate the wiring harness connectors for each fuel injector. Start the vehicle. Remove the wiring harness connector from each injector, one at a time.

    2

    Listen to the sound of the engine when you pull the wiring harness connector off each individual injector. If the engine speed suddenly slows or the engine runs rough, that injector is working. If there is no change in the sound of the engine, or if it does not run worse, then that injector is either bad or clogged.

    3

    Plug that injector back in, and repeat the procedure for the next injector.

    4

    Run fuel injection cleaner through the fuel injection system (injector cleaner kits are available at most auto parts stores -- follow the instructions for the brand you purchase), then repeat the test. If the engine runs poorly each time you pull a wiring harness connector off, you have corrected the problem. If not, there is a problem with the injector and it must be replaced.

Senin, 04 Mei 2009

Common Nissan Ignition Module Symptoms

Common Nissan Ignition Module Symptoms

The ignition module helps a vehicle's ignition system maintain enough spark to start the engine, and any problems in its components can adversely impact the car's performance. Nissan, a Japanese automobile manufacturer, recalled over 2.1 million cars worldwide in 2010 because of ignition module problems in several of its vehicles, such as the 2003 Pathfinder and Xterra. Symptoms of a ignition control problem in a Nissan are similar to those in other vehicles.

Stalling

    Faulty electrical relays inside of a Nissan's ignition module can cause the engine to lose power and fail to crank when the ignition switch is turned. The vehicle may suddenly cut off while you are driving, particularly when decreasing speed, and will often not start again. This may be a result of silicon vapor forming on the wires of the electrical relay, which supplies electricity to the ignition module.

Temperature Problems

    If your Nissan's engine does not maintain a stable temperature, the ignition module may be faulty. The engine's temperature is regulated by a heat sensor that sends data to a gauge on the vehicle's dashboard. If the temperature rises above normal, the pointer on the gauge will rise, indicating the engine is too hot. If this happens, the vehicle may have problems accelerating and suddenly stall, but will restart once the engine cools off. This cycle of overheating, shutting down and restarting will continue until excessive heat damage prevents the engine from starting at all.

Poor Acceleration

    A bad ignition module on a Nissan can cause acceleration issues. The vehicle may jerk or tremble when you hit the gas pedal. Instead of speeding up, it may slow down or hesitate at increased speeds, especially when moving from a complete stop. You may also feel strong vibrations from the engine while driving at high speeds.