See Figures 1, 2, 3 and 4
- Remove the air cleaner on V6 and V8 engines. On 4 and 6-cylinder in-line engines, removal of a Thermactor (air) pump mounting bolt and drive belt will allow the pump to be moved to the side and permit access to the distributor. If necessary, disconnect the Thermactor bypass valve and air supply hoses as well.
- Remove the distributor cap and position the cap and ignition wires to the side.
- Disconnect the wiring harness plug from the distributor connector. Disconnect and plug the vacuum hose(s) from the vacuum diaphragm assembly, if so equipped.
DuraSpark III and EEC-IV Thick Film Integrated (TFI) ignition systems are not equipped with a vacuum diaphragm assembly.
- Rotate the engine (in normal direction of rotation) until No. 1 piston is on TDC (Top Dead Center) of the compression stroke. The TDC mark on the crankshaft pulley and the pointer should align, causing the rotor tip to point towards the No. 1 position of the distributor cap (if it was installed).
- On DuraSpark I or II systems, turn the engine a slight bit more (if required) to align the timing marks or protrusion of the stator (pick-up coil) assembly with the nearest tooth on the armature. On DuraSpark III, the distributor sleeve groove (when looking down from the top) and the cap adaptor alignment slot should align. On models equipped with EEC-IV (1984 and later), remove the rotor (2 screws) and note the position of the polarizing square and shaft plate for installation reference.
- Scribe a mark on the distributor body and engine block to indicate the position of the rotor tip and position of the distributor in the engine. DuraSpark III and some EEC-IV system distributors are equipped with a notched base and will only locate at one position on the engine.
- Remove the hold-down bolt and clamp located at the base of the distributor. Some DuraSpark III and EEC-IV system distributors are equipped with a special hold-down bolt that requires a Torx® Head Wrench for removal. Remove the distributor from the engine. Pay attention to the direction the rotor tip points when the drive gear disengages. For installation purposes, the rotor should be at this position to insure proper gear mesh and timing.
- Avoid turning the engine, if possible, while the distributor is removed, since this will throw off the timing adjustment. If the engine is turned from its TDC position, TDC timing marks will have to be reset before the distributor is installed.
See Figure 5
- If the engine was rotated with the distributor removed, rotate the engine again until the no. 1 piston is on TDC of the compression stroke.
- Rotate the distributor by hand to make sure it turns freely. Visually inspect for the presence of a base O-ring, if so equipped.
- Position the distributor in the engine with the rotor aligned to the marks made on the distributor, or to the place the rotor pointed when the distributor was removed. (If a new distributor is being installed, rotate the engine until the timing marks align and the rotor is pointing towards the no. 1 cap terminal.) The stator and armature, or polarizing square and shaft plate should also be aligned. Engage the oil pump intermediate shaft and insert the distributor until fully seated on the engine.
- If the distributor does not fully seat, turn the engine slightly to fully engage the intermediate shaft. If the armature and stator assembly poles cannot be aligned by rotating the distributor in the block, pull the distributor out of the block enough to rotate the shaft and engage a different distributor gear tooth.
- Follow the above procedures on models equipped with an indexed distributor base. Make sure when positioning the distributor that the slot in the distributor base will engage the block tab and that the sleeve/adaptor slots are aligned.
- After the distributor has been fully seated on the block, install the hold-down clamp and bolt. On models equipped with an indexed base, tighten the mounting bolt. On other models, snug the mounting bolt so the distributor can be turned for ignition timing purposes.
- Reconnect the wiring harness plug to the distributor connector.
- On vehicles equipped with a DuraSpark III ignition system (except the 6-232 engine), check and adjust the rotor alignment, as necessary. For details, please refer to the ignition diagnosis and testing procedures found in Engine Electrical of this repair guide.
- Install the distributor cap and ignition wires.
- If removed, install the air cleaner or Thermactor components.
- Check and reset the ignition timing, as necessary, on applicable models. Reconnect vacuum hose(s) to the vacuum diaphragm assembly, if so equipped.
A silicone compound is used on rotor tips, distributor cap contacts and on the inside of the connectors on the spark plugs cable and module couplers. Always apply silicone dielectric compound after servicing any component of the ignition system. Various models use a multi-point rotor, which does not require the application of dielectric compound.