Distributor Cap

A literal cap that covers the ignition distributor and helps distribute electricity to the spark plugs via spark plug wires. This is a wear item that is often replaced as part of a major or complete tune up service.

Inside the distributor cap is what is called the ignition rotor- not to be confused with a brake rotor.

As the engine is turning, the rotor turns and supplies spark from the ignition coil to the proper spark plug wires that come out the top of the distributor cap.

Moisture inside the cap can cause the spark to jump and fire the wrong spark plug wire at the wrong time. This will cause engine misfire, backfiring and hard starting of your car or truck- especially on cold damp mornings.