Ignition Timing: Adjustments

ENGINE TUNE-UP [KJ]
Preparation
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 (NGS tester) to the DLC-2 and select the "PID/DATA MONITOR AND RECORD".
6. Select the "RPM" on the NGS display.


Ignition Timing
1. Perform "Preparation" above.
2. Verify that the idle speed is within the specification.

Specification: 600 - 700 (650 ± 50) rpm

^ If not as specified, adjust the idle speed.




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

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

Specification: 550 - 750 rpm

^ If not as specified, adjust the idle speed. (see below)




5. Connect the SST (timing light) to the ignition timing inspecting harness with the arrow on its cramp facing the connector.




6. Verify that the ignition timing is within the specification.

Specification: BTDC 6 - 8° (7 ± 1°)

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

7. Disconnect the SST (system selector).
8. Verify that the ignition timing is within the specification.

Specification: -5° - 15° BTDC


Idle Speed
1. Perform "Preparation" and "Ignition Timing" checks above.
2. Verify that the idle speed is within the specification.

Specification: 600 - 700 (650 ± 50) rpm

^ If not as specified, adjust as follows.




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




4. Adjust the idle speed by turning the air adjusting screw.

Specification: 600 - 700 (650 ± 50) rpm

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

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




^ 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.


Idle Mixture



8. Insert an exhaust gas analyzer to the tailpipe.
9. Verify that the CO and HC 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.