Ignition System: Testing and Inspection

Preconditions
Idle speed 950 ±50
Ignition timing 0° ±3°
Idle switch closed

Checking Timing Advance:

Testing
- Fit vacuum tee to pressure hose between EZ control unit and intake manifold.
- Connect hand-held vacuum/pressure pump to tee. Be sure connections are tight.
- Connect timing light with advance capabilities.
- Start engine.
- Pinch off pressure line between tee connection and intake manifold.
- Apply 300 mmHg vacuum with hand pump.
- Run engine at 3000 rpm.
- Ignition timing should be 40° ±3° BTDC.
- Using hand pump, increase vacuum to 1312.5 mmHg.
- Ignition timing should be 21° ±3° BTDC.