DIS Control Modules
The distributor cap is the connection for the wires that connect to the spark plugs. Inside the distributor cap is a rotor that rotates around and sends an electrical signal down the wires to the spark plugs which ignites the fuel mix in the chamber and moves the piston. Distributor caps and rotors are very important to engine function. They are often both replaced in a major tune up, but can cause problems in between tune ups as well. Generally it is recommended that the distributor and rotor are replaced about every 60,000 miles or five years. The electrical signal from the rotor to the wire is a spark, which can cause corrosion. The distributor and rotor can be replaced separately but often are replaced as one unit. Working on the distributor is usually quite straightforward because it is so accessible. The rotor requires more work since it is housed inside the distributor.