Gasoline engine ignition timing is the measurement, in degrees, of crankshaft position at the instant the spark plug fires. Ignition timing is adjusted by rotating the distributor in either a clockwise or counterclockwise direction. Timing directly effects vital engine function like gas mileage, engine performance and driveability.
Timing is checked by using a timing light that triggers in relation to spark firing. This flashing light in turn is then pointed toward timing marks on the exterior of the engine to determine relative timing condition. The timing is advanced or retarded by turning the distributor. This turning of the distributor effects the rate at which the spark plugs fire. The timing marks on gasoline Tempo/Topaz engines can be found on the harmonic balancer/crank pulley, located on the right side of the engine, as well as through a hole on the transmission case. Before attempting to adjust the engine timing, make sure these timing marks are clean and easy to read.