Ignition Timing: Adjustments
IGNITION TIMING ADJUSTMENTADJUSTMENT CONDITIONS:
Coolant temperature, 185°F-205°F.
All accessories, OFF.
Transmission, N (Neutral).
Parking Brake, ON.
1. Connect a tachometer and a timing light to the engine.
2. START engine and run at curb idle speed.
Vacuum Hose Removal:
NOTE: For high altitude (2,900 ft. or more) and California vehicles, disconnect the white stripe vacuum hose from the sub-vacuum chamber of the distributor and plug hose end.
3. Aim the timing light at the crankshaft pulley. If the flash occurs when the timing mark is before the specified degree mark, timing is advanced. To adjust, turn the distributor housing in the direction of rotor rotation. If the flash occurs when the timing mark is after the specified degree mark, timing is retarded. To adjust, turn the distributor housing against the direction of rotor rotation. If timing is within specified range, proceed to step 6. If outside specified range, proceed to next step.
Standard value
Base Timing 7° ± BTDC at curb idle speed
Ignition Timing Adjustment:
4. Loosen distributor mounting nut just enough so the distributor housing can rotate in its mounting. Turn the distributor housing until specified value is reached.
5. Tighten the mounting nut and recheck timing.
6. For high altitude (2,900 ft. or more) and California vehicles, after connecting the vacuum hose to its original position, check to be sure that the idling timing is advanced to the actual ignition timing.
Standard value
Idle Timing 12° BTDC at curb idle speed
7. Turn the engine OFF. Remove timing light and tachometer.