It's common practice to install a new distributor cap and rotor whenever new spark plug wires are installed, and on models with the ignition coil mounted in the cap, the coil must be transferred to the new cap. To access the distributor cap, remove the air cleaner assembly and loosen the distributor cap mounting screws, noting that the screws have a shoulder so they don't come completely out. On some models, the cap is held in place with latches that resemble screws; to release them, push down with a screwdriver and turn them about 1/2-turn. Pull up on the cap, with the wires attached, to separate it from the distributor, then position it to one side. The rotor will now be visible on the end of the distributor shaft; check it for cracks and carbon tracks, ensuring the center terminal spring tension is adequate while looking for corrosion and wear on the rotor tip. If replacement is necessary, detach the rotor from the shaft and install a new one, noting that some rotors are press fit and can be pried off, while others are attached with screws. The rotor is indexed to the shaft for proper installation, and the distributor cap should be checked for carbon tracks, cracks, and damage, with a small dab of silicone lubricant applied to each terminal before installation. For models with a separately mounted ignition coil, separate the cap from the distributor and transfer the spark plug wires one at a time to the new cap, ensuring not to mix up the wires. For coil-in-cap distributors, push the spark plug wire retainer latches away from the coil cover, lift the retainer ring away from the distributor cap, disconnect the battery/tachometer/coll electrical connector, remove the coil cover screws, and lift the coil out of the cap. When installing the coil in the new cap, ensure a new rubber arc seal is installed, followed by the coil screws, wires in the connector hood, and the coil cover. Finally, install the cap on the distributor, plug in the coil electrical connector, and install the spark plug wire retaining ring on the distributor cap.
Posted by GMPartsGiant Specialist