Idle Speed: Adjustments
BASIC IDLE SPEED ADJUSTMENTNOTE:
- The standard idling speed has been adjusted, by the engine speed adjusting screw, by the manufacturer, and there should usually be no need for readjustment
- Use the following procedure to adjust when the idling speed drops due to an incorrect adjustment, high idling speed, or when a load such as the air conditioning is applied on the engine.
- The adjustment, if made, should be made after first confirming that the spark plugs, the injectors, the idle air control motor, the compression pressure, etc. are all normal.
1. The vehicle should be prepared as follows before the inspection and adjustment.
- Engine coolant temperature: 85-95°C (185-205°F)
- Lights, electric cooling fan and accessories: OFF
- Transaxle: Neutral ("P" for vehicles with an automatic transaxle)
2. Connect the scan tool to the data link connector.
NOTE: When the scan tool is connected, the diagnostic test mode control terminal is grounded.
3. If the scan tool is not used, follow the steps below.
- Insert a paper clip (from the harness side) into the 1-pin connector shown in the figure.
Tachometer Connector Usage:
Caution: The paper clip should be inserted between the terminals as shown in the figure above.
- Connect a primary-Voltage-detection type of tachometer to the paper clip.
NOTE: For rpm, one-half of the actual engine rpm is indicated, so the actual engine rpm is two times the indicated value shown by the tachometer.
- Use a jumper wire to ground the diagnostic test mode control terminal of the data link connector.
4. Use a jumper wire to ground the terminal for adjustment of ignition timing.
5. Start the engine and let it idle.
6. Check the standard idling rpm.
If the scan tool is used, select item No.22 and read out the idling rpm.
Basic idle speed: 750 ± 50 rpm
NOTE:
- The engine speed may be 20 to 100 rpm lower than indicated above for a new vehicle (driven approximately 500 km: (300 miles) or less], but no adjustment is necessary.
- If the engine stalls or the rpm is low even though the vehicle has been driven approximately 500 km (300 miles) or more, it is probable that deposits are adhered to the throttle valve, so clean it.
7. If not within the standard value range, turn the engine speed adjusting screw to make the necessary adjustment.
NOTE:
- If the idling speed is higher than the standard value range even when the engine speed adjusting screw is fully closed, check whether or not there is any indication that the CTP switch (fixed SAS) has been moved.
- If there is an indication that it has been moved, adjust the CTP switch (fixed SAS). If there are no indications that it has been moved, it is possible that there is leakage as a result of deterioration of the fast idle air valve (FIAV), and, if so, the throttle body' should be replaced.
8. Switch OFF the ignition switch.
9. If the scan tool was not used, disconnect the jumper wire from the diagnostic test mode control terminal.
10. Disconnect the jumper wire from the terminal for adjustment of ignition timing, and return the connector to its original condition.
11. Start the engine again and let it run at idle speed for about ten minutes; check to be sure that the idling condition is normal.