Ignition Rotor: Service and Repair

Fig. 1 Distributor Rotor Installation & Alignment:

Late 1980-82 Rotor Alignment:

1978-8O First Design Units

NOTE:
To obtain maximum timing advance without crossfire to adjacent distributor cap electrodes, proper distributor rotor alignment is necessary using a rotor alignment tool.

1. Remove distributor cap by loosening the spring clips securing the cap to the adapter.
2. Crank the engine to align the rotor upper blade with the locating slot in the adapter so the distributor rotor alignment tool T7SP-12200-A will drop into place, Fig. 1.

NOTE: If the rotor or adapter is damaged and alignment is not possible, position the crankshaft with number one piston at top dead center, compression stroke.

3. Remove rotor alignment tool and the rotor attaching screws.
4. Remove rotor from distributor shaft.

CAUTION: Do not rotate engine after the rotor has been removed.

NOTE: When installing the rotor, coat the lower electrode blades with silicone grease approximately 1/16 inch thick.

5. Install the rotor on distributor shaft with the slot in the upper blade aligned with the locating notch on the adapter. Loosely install the attaching screws.
6. Install rotor alignment tool in the adapter with the tang on the underside of the tool engaged in the locating notch in the adapter and the slot in the rotor, Fig. 1.
7. Torque the rotor attaching screws to 15-20 inch lbs.
8. Remove rotor alignment tool and install distributor cap.

NOTE: When installing a new distributor cap, coat the brass center electrode tip with silicone grease.

Late 1979 & 1980-82 Second Design Units

NOTE: When replacing rotor, coat electrode blades with silicone grease approximately 1/32 inch thick.

The rotor on these engines can be installed by aligning the arrow molded on the top of the rotor with the large key way in slot in distributor sleeve assembly, Fig. 2. Press down on rotor until the rotor retention spring snaps into the retainer slot on the sleeve.

CAUTION: The rotor will be damaged if not properly seated on the distributor sleeve.

ROTOR ALIGNMENT

Late 1979 & 1980-82 Second Design Units
1. Remove distributor cap and rotor.
2. Rotate engine until the engine timing pointer is aligned with proper timing mark on engine damper. Make sure that No. 1 piston is on the compression stroke and not on the exhaust stroke as this will cause the distributor to be misaligned by 18O°.

NOTE: On 1979-81, proper timing mark will depend on the ignition module. On modules with number 12A199, align timing mark at TDC. On modules with number 12A244, align timing mark at 10 ATDC. On 1982, align timing mark at TDC.

3. Loosen the two sleeve assembly adjustment screws, and rotate the sleeve until alignment tool T-79P-1200A fits into the alignment slots, Fig. 2. Torque screws to 25-35 inch lbs. and remove tool.
4. Replace rotor and distributor cap.