Ignition Timing: Adjustments

ENGINE TUNE-UP [KL]
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 all electrical loads to OFF.
- 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 if 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 justing 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 a timing light to the high tension lead of No. 1 cylinder.





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

Specification: 10° ± 1° BTDC




^ If not as specified, loosen the distributor lock bolts and turn the distributor to make the adjustment.

4. Tighten the distributor lock bolts to the specified torque.

Tightening torque: 19 - 25 Nm (14 - 18 ft. lbs.)

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

Specification: 6° - 18° BTDC

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




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

8. Verify the idle CO and HC concentrations.




1. Insert an exhaust gas analyzer to the tailpipe.
2. Verify that the CO and HC concentrations are within the specified limits.
If not within the specified limits, inspect the following.
- OBD system
- HO2S
- Intake-air system
- Fuel system
- ESA control system

If the systems are normal, replace the TWC and/or the warm up TWC.