Ignition Timing: Adjustments

PREPARATION
1. Make sure that the following parts are in good order.
- Battery
- Ignition system
- Engine oil and coolant levels
- Fuses
- ECM harness connector
- Vacuum hoses
- Air intake system
(Oil filler cap, oil level gauge, etc.)
- Fuel pressure
- Engine compression
- Throttle valve
- Evaporative emission system
2. On air conditioner equipped models, checks should be carried out while the air conditioner is "OFF".
3. On automatic transmission equipped models, when checking idle rpm, ignition timing and mixture ratio, checks should be carried out while shift lever is in "N" position.
4. When measuring "CO" percentage, insert probe more than 40 cm (15.7 in) into tail pipe.
5. Turn off headlamps, heater blower, rear defogger.
6. Keep front wheels pointed straight ahead.
7. Make the check after the cooling fan has stopped.

Overall Inspection Sequence:

INSPECTION PROCEDURE

Inspection Procedure Step 1 - 2:

Inspection Procedure Step 3 - 5:

Inspection Procedure Step 6 - 10:

Inspection Procedure Step 11 - 15:

Inspection Procedure Step 16 - 19:

Inspection Procedure Step 20 - 22:

Inspection Procedure Step 23 - 27:

Inspection Procedure Step 28 - 30:

Inspection Procedure Step 31 - 35:

Inspection Procedure Step 36:

NOTE: If a vehicle contains a part which is operating outside of design specifications with no MIL illumination, the part shall not be replaced prior to emission testing unless it is determined that the part has been tampered with or abused in such a way that the diagnostic system cannot reasonably be expected to detect the resulting malfunction.