Computers and Control Systems: Adjustments

IDLE SPEED INSPECTION

NOTE: Adjustment of the idle speed is usually unnecessary. Idle speed on fuel injected vehicles is controlled by the MPI Control Unit through the Idle Speed Control Servo.

Before checking the CURB idle speed, be sure:
^ Engine coolant temperature has reached 85-95~C (185-205~F)
^ Engine cooling fan, lights and electrical accessories are OFF
^ Transaxle is in NEUTRAL or PARK.
^ Steering wheel is at a center position (power steering equipped vehicles)
^ Parking brake is applied.
^ Verify that the ignition timing is set to specifications. Refer to SPECIFICATIONS/ELECTRICAL.

CAUTION: Improper setting of the throttle valve opening will increase exhaust gas temperatures at deceleration, which will greatly reduce the life of the Catalytic Converter. Also, fuel consumption and engine braking will be affected.

Tachometer Connection:

1. Connect a tachometer. Insert a paper clip into the CRC filter connection, then connect the tachometer to the paper clip.

2. Start and run the engine for more than 5 seconds at 2,000 to 3,000 rpm.

3. Reduce the rpm and let the engine idle for 2 minutes.

4. Read the CURB idle speed. Refer to SPECIFICATIONS/MECHANICAL.

If the idle speed is not within specifications, check the MPI Control System input signals and the Idle Speed Control Servo for proper operation.
Refer to DIAGNOSIS AND TESTING PROCEDURES.