Ignition Timing: Adjustments

Refer to Specifications for correct ignition timing and firing order.
1. Ensure engine is at normal operating temperature and all electrical accessories are off.
2. Check and adjust curb idle speed.
3. Disconnect and plug distributor vacuum line from intake manifold.
4. Disconnect barometric pressure switch at higher altitudes or when barometric pressure is below 26.4 inches.
5. Connect timing light according to the manufacturer's instructions.
6. Check timing mark on crankshaft pulley and timing case. Correct spark timing is TDC at idle with no vacuum advance.
7. Loosen distributor mounting bolts to rotate distributor to advance or retard. Turn distributor clockwise to advance and counterclockwise to retard.
8. With timing at TDC, tighten mounting bolts, ensuring the distributor does not turn.
9. Reconnect vacuum hose and barometric pressure switch, if disconnected.
10. Check idle speed and adjust if necessary.