Base Idle Speed Adjustment

NOTICE: If base idle speed adjustment is required make sure the following items meet specifications for "normal" and/or "proper" operation prior to beginning the Idle Speed Adjustment procedure:

- Spark Plugs--for proper gap and operating condition.
- Fuel Injectors--for proper operation.
- Idle Air Control Motor--for proper operation.
- Cylinder Compression--tests "normal".



The basic idle speed has been factory pre-set with the engine speed adjusting screw. Further adjustment is not normally required.

If pre-set has been disturbed, if the idle speed is too high, or the idle speed drops due to an air conditioning load to the engine, perform the following adjustment procedure:

SCAN TOOL PROCEDURE
1. Set the vehicle up as follows:
- Engine coolant temperature 80-95°C (176-205°F).
- Lights, engine cooling fan, and electrical accessories are "OFF"
- Transaxle is in "NEUTRAL" or "PARK"
- Steering wheel is at a center position (on vehicles equipped with power steering).
2 Connect the scan tool to the data link connector (white).

NOTE: The connection of the scan tool grounds the diagnostic test mode control terminal.

WITHOUT SCAN TOOL PROCEDURE

Tachometer Connector:

1. Insert a paper clip into the 1-pin blue connector as shown in the illustration.
2. Connect a primary-voltage-detecting tachometer to the paper clip.

Data Link Connector (DLC):

3. Use the special tool (Diagnostic Trouble Code Check Harness) to ground the diagnostic test mode control terminal (terminal 1) of the data link connector (16-pin).

Ignition Timing Adjustment Terminal Grounded:

4. Remove the waterproof female connector from the ignition timing adjusting connector (brown).
5. Using a jumper wire, ground the ignition timing adjusting terminal.
6. Start the engine and run at idle.
7. The basic idle speed should be: 700 RPM (±50 RPM).

The engine speed may be low by 20 to 100 rpm while the vehicle is new [distance driven approx. 500 km (300 miles) or less], but no adjustment is necessary.

If the engine stalls or speed is low despite a sufficient distance driven [approx. 500 km (300 miles) or more], it is probably due to deposits on the throttle valve. In this case, clean the throttle valve.
Throttle Body Cleaning

The tachometer should read 1/3 of the actual engine speed. This means that the actual engine speed is the tachometer reading multiplied by 3.

Adjusting The Idle Speed:

8. If the basic idle speed is out of specification, adjust by turning the engine speed adjusting screw.

NOTE: If the idle speed is higher than the standard value (even with the Engine Speed Adjusting Screw turned fully "in") check to see if there is evidence of the closed throttle position switch having been moved. If the closed throttle position switch seems to have been moved, adjust it. If it does not seem to have been moved, there may be a leak caused by deteriorated Fast Idle Air Valve (FIAV). In such a case, replace the throttle body.
Throttle Body Replacement

9. Turn the ignition switch "OFF".

10. When the scan tool has not been used, remove the jumper wire from the diagnostic test mode control terminal.

11. Remove the jumper wire from the ignition timing adjusting terminal and replace the connector back again.

12. Start the engine again and run at idle for 10 minutes to make sure that the engine runs at proper idle speed.