GM Celebrity/Century/Ciera/6000 1982-1996 Repair Guide

Spark Plug Wires



Every 15,000 miles (24,000 km), inspect the spark plug wires for burns, cuts, or breaks in the insulation. Check the boots and the nipples on the distributor cap. Replace any damaged wiring. General Motors requests that you replace your spark plug wires every 30,000 miles (50,000 km).

The resistance of the wires should be checked with an ohmmeter. Wires with excessive resistance will cause misfiring, and may make the engine difficult to start in damp weather.

To check resistance, remove the distributor cap, leaving the wires in place. Connect one lead of an ohmmeter to an electrode within the cap; connect the other lead to the corresponding spark plug terminal (remove it from the spark plug for this test). The following chart gives resistance values as a function of length. Replace any wire which shows a resistance over 30,000 ohms.

0-15 in. (0-38cm): 3,000-10,000 ohms
15-25 in. (38-64cm): 4,000-15,000 ohms
25-35 in. (64-89cm): 6,000-20,000 ohms
Over 35 in. (89cm): 25,000 ohms

It should be remembered that resistance is a function of length; the longer the wire, the greater the resistance. Thus, if the wires on your car are longer than the factory originals, resistance will be higher, quite possibly outside these limits.


See Figures 1, 2 and 3

When installing new wires, replace them one at a time to avoid mix-ups. Start by replacing the longest one first. Install the boot firmly over the spark plug. Route the wire over the same path as the original. Insert the nipple firmly onto the tower on the distributor cap or coil, then install the cap cover and latches to secure the wires, if applicable.

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Fig. Fig. 1: In order to replace the plug wires, you must first unlock the plastic retainers

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Fig. Fig. 2: Grasp only the boot when removing the wires, never tug on the wire itself!

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Fig. Fig. 3: Make sure the heat shield is seated against the bump stop and lower the tabs extended over the hex on the spark plug - 3.3L engine