Ignition Timing: Adjustments

IGNITION TIMING, ADJUST

1. Connect a suitable tachometer to engine and a suitable adjustable timing light to No. 1 cylinder secondary cable. Do not puncture ignition secondary cables or boots with test probes.
2. Set parking brake, start engine and place gear selector in neutral. Run engine until warm.
3. On vehicles equipped with carburetor switch, connect a jumper wire between carburetor switch and a known good ground. Disconnect and plug vacuum line from transducer.
4. Ensure curb idle speed is set at or below specifications. Adjust as necessary.
5. Check ignition timing. If within 2° of specifications, shut engine Off and remove timing light, tachometer and carburetor ground wire. If outside of tolerance, proceed to step 6.
6. Loosen distributor hold-down arm screw, rotate distributor housing until correct timing marks are lined up, ensuring idle speed is still at or below specified curb idle speed.
7. Tighten distributor hold-down screw, then recheck idle speed and ignition timing.
8. Turn engine Off and remove timing light, tachometer and carburetor ground wire.
9. Reconnect vacuum hose.