What does a distributor cap do?

Answer by  Christian9247 (5042)

A distributor cap routes the high voltage into the correct firing order to the spark plugs. Magnetos and Battery Ignitions have distributor caps and they should be changed often.

Answer by  McCheese (1248)

The distributor cap releases excess pressure that builds up in an engine. If you open the hood of a car, you will see steam rising out of the distributor cap when the engine is under stress. Maybe the engine is revving very fast, or it's a hot day. In any case, the distributor cap keeps the engine cool.