All gasoline engines mounted on Toyota automobiles are four-stroke engines. Four-stroke engines operate by continuous and regular repetition of the following sequence:
1. Intake stroke
2. Compression stroke
3. Combustion stroke
4. Exhaust stroke
Basic principle of four-stroke engine
In order for an engine to operate smoothly under a wide range of operating conditions, the following three conditions must be satisfied:
Good air-fuel mixture
Good compression
Good spark