Ignition Timing: Testing and Inspection

Ignition timing can be thrown off for two reasons:
A problem with a sensor, which will be detected by ECM or a misalignment of camshaft to crankshaft. This last problem indicates a problem with timing belt, which is covered in Engine. There is no need to adjust engine timing after replacement of a coil.

Check procedure
1. Warm engine and let idle.
2. Turn all other electrical systems OFF.
3. Connect timing light to high-tension lead number one.
4. Check that ignition timing mark on crankshaft pulley aligns with timing mark on engine block.




Check procedure

1. Apply parking brake.
2. Warm up engine to normal operating temperature.
3. Turn OFF all electrical loads.
4. Connect timing light to number one spark plug wire.

NOTE: A rubber inspection plug has been provided in the plastic coil cover (center of the cylinder head cover) directly over the number one (1) spark plug wire. Remove the inspection plug and connect the inductive pick-up of your tachometer or timing light to the number one (1) sparkplug wire. If your tachometer/timing light inductive pick-up is too large, the coil cover will have to be removed.




5. Verify that ignition timing marks on crankshaft pulley and timing mark on timing belt cover are aligned.

Ignition timing: BTDC 80° ± 5° (at idle speed)

NOTE: Ignition timing is not adjustable.

6. If timing is not within the specified range, replace the ECM.