How to Replace the Distributor Cap on a 1988 Chevrolet truck

The distributor cap on a 1988 Chevrolet truck conducts high-voltage ignition current through the ignition wires to the spark plugs. Over time, the electrical contacts within the distributor cap wear out. This can cause the engine to misfire, to start hard and to stall. Replacing the distributor cap is an important part of a complete engine tune-up. No specialized tools are required, but it is important to connect the ignition wiring correctly, or the engine will not operate. If ignition wires show signs of deterioration, it is a good idea to replace them as well.

Tools Used: Screwdriver, Masking tape, Permanent marker

Replace Distributor Cap

Remove Distributor Cap

Follow the #1 spark plug wire from the #1 spark plug to the distributor. The #1 spark plug is at the front of the engine on the driver's side. At the distributor end of the #1 plug wire, label the wire "#1" with masking tape and a permanent marker. Note the location of this wire on the distributor cap. This will ensure correct wire installation on the new distributor cap.

Label the remaining spark plug wires at the distributor cap, again using masking tape and the permanent marker. Wires can be identified by moving clockwise around the cap from the #1 wire. In clockwise order, the wires of a 1988 Chevrolet V-8 engine are 1, 8, 4, 3, 6, 5, 7 and 2. This is the "firing order" of the engine's cylinders.

Remove the ignition wires from the distributor cap by pulling straight up on the wire boot. Wires can usually be pulled straight off. If necessary, the boot can be rotated or pushed gently side to side to help break it free of the cap. Do not pull or twist on the wire itself, as this can damage the wire.

Remove the ignition coil feed and module wires from the distributor cap.

Depress and rotate (to release) each of the four distributor cap retainers using a screwdriver. Lift the cap off the distributor.

Remove the four ignition coil cover screws from the cap and remove the coil cover. Remove the four coil retaining screws and remove the ignition coil, spring and rubber seal from the cap.

Install Distributor Cap

Install the ignition coil, spring and rubber seal in the new distributor cap. Install the four coil retaining screws and tighten securely. Install the coil cover and tighten screws securely.

Install the new cap on the distributor. Depress and rotate the four cap retainers with a screwdriver to secure the cap on the distributor.

Connect the ignition coil and module wires at the distributor cap.

Connect the ignition wires in the appropriate locations on the distributor cap, per the masking tape labels and firing order. Remove the masking tape from the wires.

Tips & Warnings

While replacing the distributor cap can improve engine performance, it is also important that other ignition components be in good condition. Ignition wires, spark plugs and other components should be examined and replaced as necessary.

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