Ignition Timing Adjustment

1. Remove the rubber cap from the inspection window of the cylinder block.
2. Start the engine and allow it to warm up (cooling fan comes on).
3. Disconnect the vacuum hoses from the vacuum advance diaphragm and, while the engine idles, check each hose for vacuum and plug the hoses.
a. The inside hose (# 12 for fuel-injected engine or # 2 for carbureted engine) should have vacuum.
b. The outside hose (# 15 for fuel-injected engine or # 25 for carbureted engine) should not have vacuum.

NOTE: If vacuum is not as specified, see Timing Control System.

4. Reconnect the hoses to the vacuum advance diaphragm, then connect an advance tester to the engine. While the engine idles, point a timing light toward the flywheel (for M/T), or the drive plate (for A/T).
5. Adjust ignition timing, if necessary, to the following specifications:

Ignition Timing Specification:

Carbureted engine:
Manual Transmission: (at 700-800 rpm in neutral)
49 STATE and HIGH ALTITUDE: 22-26° BTDC (Red mark)
CALIFORNIA: 20° BTDC (Red mark)
Automatic Transmission: (at 650-750 rpm in gear)
ALL MODELS: 13-17° BTDC (Red mark)

Fuel-Injected engine:
ALL MODELS: 13-17° BTDC (Red mark) (at 700-800 rpm in neutral)







6. Loosen the distributor adjusting bolts (and nut for fuel-injected engine), and turn the distributor housing counterclockwise to advance the timing, or clockwise to retard the timing.
7. Tighten the adjusting bolts (and nut for fuel-injected engine), recheck the timing.







8. Disconnect the outside vacuum hose (# 15 or # 25) from the diaphragm and apply vacuum (more than 500 mmHg, 20 in.Hg), to the outside diaphragm with a vacuum pump. The timing mark (Red) should advance an additional 6°.
9. Disconnect the vacuum hoses from the vacuum advance diaphragm and pinch the end of the hoses using fuel line clamps, 07614-0050100. The timing should be 4° BTDC.
10. If advance is not as specified, check the advance diaphragm and the distributor advance mechanism.