Operation CHARM: Car repair manuals for everyone.

Ignition Timing: Testing and Inspection

1. Precondition the engine as follows:
- Engine coolant temperature greater than 185°F.
- Lights, electric cooling fan, and all electrical accessories off.
- Transaxle in neutral or park.
- Steering wheel in the neutral position.
2. Connect a timing light.

Connecting Tachometer:





3. Insert a paper clip into the CRC filter connector and connect a tachometer to the inserted clip.

4. Verify the curb idle speed.

Curb idle speed: 750 ± 100 rpm.

Ignition Timing Adjustment Connector:





NOTE: If using Multi-Use Tester either disconnect the tester or do not connect the ignition timing jumper lead.
5. With the engine off ground the ignition timing adjustment terminal with a jumper lead.
6. Start the engine and allow it to run at curb idle speed.

Measuring Ignition Timing:





7. Verify the basic ignition timing.

Basic Ignition Timing: 5° BTDC.

Adjusting Ignition Timing:





8. If necessary loosen the crank angle sensor mounting nut and adjust timing by rotating the crank angle sensor.
9. Stop the engine and disconnect the grounding jumper.
10. Start the engine and allow it to operate at curb idle speed.

11. Verify the actual ignition timing.

Actual Ignition Timing: 8° BTDC.

NOTE: Actual ignition timing may vary slightly under the direction of the engine control module. If necessary re-check basic ignition timing. If it is still correct no further action is required.