How the Ignition System Works
Any kind of fire requires three things: fuel, air, and an ignition source. With the exception of electric vehicles and diesel engines, most engines use a spark to ignite the fuel and air inside the engine.
The ignition system in your car is designed to ignite the air-and-fuel mixture at the right time, when the engine has compressed the mixture and it is ready to explode and drive the engine in a rotating motion. To do this, it uses a high-voltage spark that is timed to the engine through the computer or, in older cars, through a mechanical device called a distributor.
Spark Plug Spark plugs generate the spark ...