Idle Speed: Adjustments

NOTE: Adjustment of idle speed is usually not required. If idle speed is out of specification check and verify the operation of the idle speed control system. Refer to COMPUTERS AND CONTROL SYSTEMS.

1. Precondition the vehicle as follows:
a. Engine coolant temperature greater than 185 degrees F.
b. Lights, electric cooling fan, and all electrical accessories off.
c. Transmission in neutral or park.
d. Steering wheel in the neutral position.
e. Ignition timing verified correct.

Tachometer Lead Connector Location:

2. Insert a paper clip in the idle speed connector (blue).

Tachometer Installed:

3. Connect a tachometer to the inserted paper clip.
NOTE: The tachometer should read at 1/3 of the actual engine speed. Multiply the reading by 3 to obtain the correct RPM.

Data Link Connector (DLC):

4. Use a jumper wire, ground the self diagnosis/data transfer switching terminal (terminal 1) of the diagnostic connector. The connector is located inside the passenger compartment, under the dash.

Ignition Timing Adjustment Terminal Location:

5. With the ignition OFF, remove the waterproof plug from the connector (brown) for ignition timing adjustment and ground the terminal using a jumper wire.
6. Start the engine and allow it to run at curb idle speed.
7. Verify Idle Speed.

Curb Idle Speed 700 ± 50 rpm

Idle Speed Adjustment Location:

8. If the idle speed is NOT as specified, adjust the speed adjusting screw.
9. Stop the engine, disconnect jumper wires, remove tachometer and reinstall waterproof plug in the connector for ignition timing adjustment.
10. Start the engine and confirm that idling condition is normal.