Ignition Timing: Adjustments

Timing specifications for 2.OL (VIN K) and (VIN M) engines are listed on the Vehicle Emissions Control Information Label. When using a timing light, connect an adapter between the spark plug and the spark plug wire, or use an inductive type pick-up. Do not pierce the plug lead. Once the insulation of the spark plug cable has been broken, current will jump to the nearest ground, and the spark plug will not fire properly. Always follow the label procedures when adjusting timing. After the timing has been set, clear the ECM memory as called for.

Typical Magnetic Timing Probe Hole:

VIN K and VIN M engines also incorporate a magnetic timing probe hole for use with special electronic timing equipment.

The averaging method is a process in which the timing of each cylinder can be brought into closer agreement with the base timing specifications. The averaging method involves the use of both the No.1 and No.4 spark plug wires to trigger the timing light.

Grounding The Diagnostic Terminal:

1. See Vehicle Emission Control information label in the engine compartment and follow instructions on the label.
2. With engine at operating temperature, air cleaner installed and air conditioning off (if equipped), electric cooling fan off and automatic transaxle in "D" Drive (manual transaxle in "N" Neutral) connect the inductive pick-up of the timing light on number one spark plug wire. Verify no "Service Engine Soon" light.
3. Ground the Assembly Line Diagnostic Link (ALDL) connector located under dash by jumping "A" to "B" terminals. "Service Engine Soon" will begin flashing.
4. Record position of timing mark.
5. Repeat step 3 but use the number 4 spark plug lead. Take the total of the two recorded timing marks and divide by two to come up with average timing.

Example: No.1 cyl. 4° + No. 4 cyl. 8° = Total 12°, 12 / 2 = 6° Average Timing.

6. If a change is necessary, subtracting the average timing from timing specifications will determine the amount of timing change on No.1 cylinder. Example: Spec. Time of 8° - Avg. Time 6° = + 2° of timing.
Spec. Time of 8° - Avg. Time 10° = -2° of timing.
7. Remove ground from ALDL connector.
8. To clear the ECM memory, disconnect the ECM harness from the positive battery pigtail for 10 seconds with the key in the "OFF" position.