Idle Speed Testing and Adjustment
NOTE:1. The basic Idle speed has been factory-adjusted with the engine speed adjusting screw and does not normally require adjustment.
2. If adjustment has been disturbed, or if the idle speed is too high or it drops owing to application of air conditioning load to the engine, perform the following step to make adjustment.
3. If the adjustment is required, first check that the ignition plug, injector, idle air control motor and compression pressure are normal.
(1) Before starting the inspection and adjustment procedures, set the vehicle in the following conditions:
- Engine coolant temperature: 80 to 95°C (176 to 203°F)
- Lights, electric cooling fan, accessories: OFF
- Transaxle: Neutral (P range on vehicles with automatic transaxle)
- Steering wheel: Straightforward position
(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.
(3) If not using the scan tool, proceed as follows:
1) Install a paper clip to the 3-pin connector from the harness side as shown in the illustration. Do not disconnect the connector.
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.
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).
(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) Check the basic idle speed.
Basic idle speed: 700 ± 50 r/min
NOTE:
1. The engine speed may be low by 20 to 100 r/min while the vehicle is new [distance driven approx. 500 km (300 miles) or less], but no adjustment is necessary.
2. 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. (Refer to P.13A-52.)
3. In the case of a DOHC engine, 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.
(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 engine speed adjusting screw fully tightened, check to see if there is evidence of the closed throttle position switch being 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.
(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.