To adjust the ignition timing on an older car with a distributor, wire up a timing light and run the engine with the light pointed at the crankshaft and the pulley that extends from it. The notch on the pulley is the top dead center, and it should flash when the timing light hits it. Three to five degrees before top dead center is the ideal position for the distributor.
Turn the distributor toward this ideal position. The ignition timing is fully adjusted when the timing light begins to flash at that position.
Newer engines are designed to adjust engine timing automatically. If dashboard sensors call attention to a problem in the engine, take the car to a professional to install a new performance chip.
Ignition timing occurs in spark ignition combustion engines. It happens when a spark occurs in the combustion chamber toward the end of the engine's compression stroke. While every vehicle has an individual preferred ignition timing, it is critical that it is set correctly. If the spark happens too early or late during the engine's cycle, vibrations and damage can occur. Additionally, incorrect ignition timing adversely impacts the fuel economy, power and the engine's lifespan.
A number of factors can negatively affect ignition timing. Incorrect fuel injector and intake valve timing, spark plug condition, fuel temperature, fuel impurities or the temperature of the engine can all throw off ignition timing. It is crucial to reset the timing whenever any changes to the engine occur.