Ignition Timing: Adjustments

Distributor Vacuum Diaphragm:

1. Disconnect and plug diaphragm vacuum hoses.
2. Ground Self Test Input (STI) connector.
3. Warm engine to operating temperature.
4. Turn all electrical loads "OFF."
5. Connect a timing light.
6. Check idle speed and adjust if needed:

Idle Speed 850 ± 50 rpm

7. Connect Rotunda Timing Analyzer (059-00014) or equivalent.

Timing Marker:

8. Check timing:

Base Timing: 12° ± 1° BTDC

9. If marks are not aligned, loosen distributor mounting bolts and turn distributor.
10. Tighten mounting bolts.
11. Reconnect vacuum hoses.
12. Remove jumper wire from STI connector.
13. Remove timing light.