Learn to identify the ignition system' s vacuum sensing device. Acquire the knowledge in order to test for a faulty vacuum sensing device. Ignition timing is the single, most critical adjustment for a gasoline engine. Assuming the engine is in good mechanical condition, there are no vacuum leaks, and the fuel mixture is correct, then the ignition timing can affect the net power yield from the fuel.
Improper timing can significantly change a vehicle's mpg.
Three types of timing are used for gasoline engines. Each has a specific purpose. Static timing establishes a physical relationship between engine crankshaft position and the distributor. This is fixed and should not change. Thus, mechanical timing advances are used.