Ignition Timing: Adjustments

ENGINE TUNE-UP [KJ]
1. Prepare for the engine adjustment.
1. Warm up the engine to normal operating temperature.
2. Shift the selector lever to P or N position.
3. Turn off all electrical loads.
- Headlight
- Blower motor
- Rear window defroster
- A/C
- P/S

4. Wait until the cooling fan stops.




5. Connect the SST (WDS or equivalent) to the DLC-2.
6. Access RPM PID.




2. Short the DLC terminal TEN to body ground.
1. Connect the SST (system selector) to the DLC.
2. Set switch A to position 1.
3. Set the test switch to SELF TEST.

3. Verify the ignition timing and adjust as necessary.
1. Verify that the idle speed is within the specification.

Specification: 550 - 750 rpm




If not as specified, adjust the idle speed by turning the air adjusting screw.

Caution: The throttle adjusting screw is set at the factory and must not be adjusted. Any adjustment will negatively affect the engine performance.




2. Connect the SST (timing light) to the ignition timing inspecting harness with the arrow on its cramp facing the connector.
3. Verify that the ignition timing is within the specification.

Specification: 7° ± 1°) BTDC

If not as specified, inspect the following.
- OBD system
- CMP sensor
- CKP sensor

4. Verify that the idle speed is within the specification.

Specification: 650 ± 50 rpm




If not as specified, adjust the idle speed by turning the air adjusting screw.

Caution: The throttle adjusting screw is set at the factory and must not be adjusted. Any adjustment will negatively affect the engine performance.

5. Disconnect the SST (system selector).
6. Verify that the ignition timing is within the specification.

Specification: -5° - 15° BTDC

7. Verify that the idle speed is within the specification with the following load conditions.




*1: Excludes temporary idle speed drop just after the electrical loads are turned on.
*2: Blower motor is operating at high speed. Headlight is on. Rear window defroster switch is on.

If not as specified with all load conditions, inspect the IAC valve.
If not as specified with some load conditions, inspect the related input switches, harnesses and connectors.

8. Verify the idle CO and HO concentrations.




1. Insert an exhaust gas analyzer into the tailpipe.
2. Verify that the CO and HO concentrations are within the specified limits.
If not within the specified limits, inspect the following.
- OBD system
- H02S
- Intake-air system
- Fuel system
- ESA system

If the systems are normal, replace the TWC and/or WU-TWC.