The 3800 engine is a 3.8 liter V-6 engine that began as a V-8 engine with two cylinders left off. It was first introduced in a Buick in 1962. Since then it has undergone two major updates, the second in 1995. It has become the mainstay of V-6 engines for cars throughout the General Motors line. All 2002 Buicks that were equipped with a V-6 used the 3800. Of the service bulletins issued by General Motors for 2002 Buicks with the 3800, only seven relate to fuel issues and none involves problems with restarting after fueling. Motorists occasionally have problems starting a car after refueling, but it usually has nothing to do with the type of car or engine.
Remove the gas cap, then try starting the car again. If the fuel tank gets too full it can create a vacuum that prevents gas from reaching the engine. The purge valve in the fuel tank normally prevents this. After the engine has started, put the gas cap back on. This problem will not affect drivability or cause any other problems. Mention it on your next routine service visit.2
Wait at least five minutes and then try again. As cars age, some develop a problem starting when the engine is hot. Try starting every five minutes. Do not crank too frequently or you could overheat the starter. If this resolves the problem, schedule a service appointment, as it could indicate a more serious underlying problem.3
Have a mechanic check for tainted fuel. If the fuel you used has been contaminated either your car will not start at all or will run very roughly after starting. You will need to get the car to a repair shop right away to have the fuel tank and lines purged and cleaned by a professional mechanic.4
Have the car towed to a repair shop if no simple solution works. Sometimes a problem builds over time and may just coincidentally exhibit symptoms after fueling. For example, systems that control the fuel to air ratio could be deteriorating in a way that does not yet affect cold starts, in which the oxygen is dense, but does inhibit hot starts, in which the oxygen content is thinner. If the problem has occurred several times, you should schedule an appointment at an auto repair shop. Recurring symptoms are indicators of a problem which you want to have corrected.