GM Service Manual Online
For 1990-2009 cars only

Important: Ignition timing could not be adjusted for Direct Ignition System, Euro Stage III.

Inspect and adjust the ignition timing in the following procedures:


    Object Number: 1201348  Size: SH
  1. Warm up the engine to the normal operating temperature.
  2. Turn off the lamp and audio system and shift the shift gear lever in neutral.
  3. Connect terminal A and terminal C of ALDL connector using the wire (1) or connect the scan tool (2) with the ALDL connector.

  4. Object Number: 1224541  Size: SH
  5. Connect the timing light (1) with No. 1 cylinder high tension cable and check the specified value for the ignition timing, flashing notch on the crankshaft pulley.
  6. Specification
    The ignition timing is 950 RPM 10 degrees BTDC.


    Object Number: 1224542  Size: SH

    Important: In flashing the timing light, if crankshaft pulley notch (2) is matched with the mark 10 (1) for timing check, the ignition timing is 10 degrees BTDC.

  7. If the ignition timing exceeds the specified value, loosen the distributor bolts and adjust it to the specified ignition timing by turning the distributor body.