Adjustment Procedure

IGNITION TIMING PROCEDURE

CAUTION: This procedure can only be performed if the basic ignition timing has failed the driveability test procedure. The distributor must never be turned under any other circumstances.

1. Connect a suitable Power Timing Light to number one cylinder (refer to the equipment manufacturer's instructions for correct connecting procedures) or a suitable magnetic timing unit (use a negative 10~ offset when required).

Do not puncture cables, boots or nipples with test probes. Always use proper adapters. Puncturing the spark plug cable with a probe will damage the cables. The probe can separate the conductor and cause high resistance. In addition breaking the rubber insulation may permit secondary current to arc to ground.

2. Connect tachometer to engine.

3. Turn selector switch to the appropriate cylinder position.

4. Start engine and run until operating temperature is obtained.

5. Disconnect and reconnect the "coolant sensor" connector. The power loss lamp must turn on.
6. Aim Power Timing Lamp at timing hole in bell housing or read magnetic timing unit. If flash occurs when timing mark is before specified degree mark, timing is advanced.

If flash occurs when timing mark is after specified degree mark, timing is retarded.

7. Loosen distributor hold-down arm screw just enough so the distributor housing can be rotated in its mounting. Turn distributor housing until specified label value is reached. Tighten the hold-down arm screw and recheck timing. Remove timing device.

8. Turn engine off. Disconnect and reconnect battery positive (+) connection at the quick disconnect.

9. Start the engine and let speed stabilize for one minute. The power loss lamp should be off.

10. Set the parking brake.

11. Apply the service brakes and place transmission in drive (auto trans only).

12. Engine speed should be within label specifications +/- 100 rpm's. If engine speed is okay proceed to next step. If engine speed is above specification, perform idle set rpm's adjustment.

13. Turn engine off and check codes on readout box. Codes 88-12-55 should only be shown (88-12-33- 55 without A/C).

14. Turn ignition switch off, remove tachometer and diagnostic readout box.