GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Geo 🢒 1996 🢒 Metro 🢒 Engine 🢒 Engine Controls - 1.0L 🢒 Ignition Timing Adjustment
  1. Start the engine.
  2. Run the engine until normal operating temperature is attained.
  3. Perform all of the following actions:
    4. • Turn OFF all the electrical loads (the windshield wipers, the radio, the headlights, the rear window defogger and the HVAC blower motor).
    • Turn OFF the A/C.
    • Place the gearshift control lever in Neutral (manual transaxle models) or place the gearshift control lever in Park (automatic transaxle models).
    • Apply the parking brake.

    Object Number: 56509 Size: SH
  4. Connect an inductive timing light to the secondary ignition (spark plug) wire of the No. 1 cylinder.

    5. Object Number: 236945 Size: MH
  5. Access the duty check data link connector (8) located next to the PCM (7) behind the glove box.

    6. Object Number: 56489 Size: SH
  6. Connect a fused jumper wire (2) from the duty check data link connector (1) cavity 4 to the duty check data link connector cavity 5.

    7. Object Number: 56491 Size: SH
  7. Check the ignition timing with the inductive timing light (1). Refer to the Vehicle Emission Control Information Label for the correct ignition timing.

    8. Object Number: 56495 Size: SH
  8. Adjust the ignition timing if the ignition timing is not within the vehicle specification.
    9. 8.1. Loosen the distributor housing flange bolts (1).
    8.2. Rotate the distributor in order to adjust the ignition timing.
       • Rotate the distributor clockwise (2) in order to advance the ignition timing.
       • Rotate the distributor counterclockwise (3) in order to retard the ignition timing.
    8.3. Recheck the ignition timing.
  9. Repeat step 8 until the ignition timing is within the specification.

    10. Notice: Use the correct fastener in the correct location. Replacement fasteners must be the correct part number for that application. Fasteners requiring replacement or fasteners requiring the use of thread locking compound or sealant are identified in the service procedure. Do not use paints, lubricants, or corrosion inhibitors on fasteners or fastener joint surfaces unless specified. These coatings affect fastener torque and joint clamping force and may damage the fastener. Use the correct tightening sequence and specifications when installing fasteners in order to avoid damage to parts and systems.

  10. Tighten the distributor housing flange bolts.

    11. Tighten
    Tighten the distributor housing flange bolts to 15 N·m (11 lb ft).

  11. Remove the jumper wire from the duty check data link connector.
  12. Check that the ignition timing advances when the engine speed increases.
  13. Remove the timing light.