Ignition Timing: Testing and Inspection

Ignition Timing Control Inspection
1. Connect a timing light to the engine.
2. Crank the engine.




3. Verify that the timing mark (yellow) on the crankshaft pulley and the mark on the timing belt cover are aligned.

Specification: BTDC 6-8°

4. If not as specified, loosen the lock bolt and adjust by turning the distributor.
5. If adjustment by turning distributor is not possible, check the following.
a. PCM terminal voltage - IGT control signal and related wiring harnesses and connectors.
b. Camshaft position sensor.
c. Ignition control module and related wiring harnesses and connectors.




6. Connect the Special Service Tool (System Selector) to the data link connector.
7. Set switch A to position 1.
8. Set the test switch to SELF TEST.
9. Start the engine.




10. Verify that spark retards as the engine warms up.
11. If not, check Engine coolant temperature sensor.
12. Disconnect the Special Service Tool (System Selector).
13. Warm up the engine to normal operating temperature.
14. Verify that the ignition timing is correct.




15. Increase the engine speed and verify that the ignition timing advances accordingly.
16. If not, check the Mass air flow sensor.