Of the engines covered by this guide, only the 5.0L engine utilizes a distributor ignition system. The 3.8L and 4.6L engines use distributorless electronic ignition systems, in which separate ignition coils fire the spark plugs directly through the secondary ignition wires.
It is normally a good idea to inspect the distributor cap and rotor any time you perform a tune-up, which includes checking the spark plug wires for wear, damage or excessive resistance.
REMOVAL & INSTALLATION
See Figures 1 through 6
- Disconnect the negative battery cable for safety purposes.
- If equipped, remove the protective rubber boot from the distributor assembly by carefully lifting at the edges.
Depending on the reason you have for removing the distributor cap, it may (in some cases) make more sense to leave the spark plug wires attached. This is the case, for example, if you are testing spark plug wires, or if removal is necessary to access other components (and wire play allows you to reposition the cap out of the way).
- Tag and disconnect the spark plug wires from the distributor cap towers. THIS STEP IS CRITICAL. Do not attempt to rewire the cap based only on a diagram; this often leads to confusion and miswiring.
- Disconnect the ignition coil lead from the distributor cap.
- Loosen the distributor cap hold-down screws and/or release the hold-down clamps. Most original equipment distributors and caps utilize the hold-down screws.
- Carefully lift the distributor cap STRAIGHT up and off the distributor, in order to prevent damage to the rotor blade and spring.
- If necessary, grasp the rotor by hand and pull upward to remove it from the distributor shaft and armature.
- Inspect both the distributor cap and rotor for damage; replace as necessary.
- Align the locating boss on the rotor with the hole on the armature, then carefully seat the rotor on the distributor shaft. Make sure the rotor is fully seated, but do not force it, as the plastic components often break easily.
- Position the distributor cap on the base, noting the square alignment locator.
- Secure the cap using the hold-down screws and/or the release clamps. If used, tighten the cap hold-down screws to 18-23 inch lbs. (2.0-2.6 Nm).
- Connect the ignition coil lead to the center tower of the distributor cap.
- If removed, connect the spark plug wire leads as tagged during removal.
- If equipped, reposition and seat the protective rubber boot over the distributor assembly.
- Connect the negative battery cable.
See Figures 7 and 8
After removing the distributor cap and rotor, clean the components (both inside and outside of the cap) using soap and water. If compressed air is available, carefully dry the components (wearing safety goggles) or allow the parts to air dry. You can dry them with a clean, soft cloth, but don't leave any lint or moisture behind.
Once the cap and rotor have been thoroughly cleaned, check for cracks, carbon tracks, burns or other physical damage. Make sure the distributor cap's carbon button is free of damage. Check the cap terminals for dirt or corrosion. Always check the rotor blade and spring closely for damage. Replace any components where damage is found.