Basic Idle Speed
NOTE:
ALWAYS check TPS adjustment after adjusting basic idle speed. See THROTTLE POSITION SENSOR (TPS)
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NOTE:
For Data Link Connector (DLC) location, see TESTS W/CODES
article.
NOTE:
Ensure vehicle is at normal operating temperature with all lights, cooling fan and accessories off. Shift transmission into Neutral or Park position.
- Insert paper clip or appropriate probe into tachometer connector. Connect a primary voltage detecting type tachometer to paper clip.
- On all models with 16-pin DLC connector, connect a jumper wire between data link terminal No. 1 and vehicle ground. See Fig 2 . On all models with 12-pin DLC connector, connect a jumper wire between data link connector terminal No. 10 and vehicle ground. See Fig 1 .
- Connect a jumper wire between ignition timing adjustment connector and vehicle ground. See IGNITION TIMING ADJUSTMENT CONNECTOR LOCATION table under IGNITION TIMING.
- Start and run engine at idle. Check basic idle speed. See IDLE SPEED SPECIFICATIONS table. If idle speed is not within specification, turn engine speed adjusting screw until correct engine speed is obtained. See Fig 3 . Access to speed adjusting screw is obtained by removing rubber plug on throttle body.
- If idle speed cannot be lowered by turning engine speed adjusting screw, determine if fixed speed adjusting screw (stop screw contacting throttle lever) has been adjusted. See FIXED SPEED ADJUSTING SCREW for procedure.
- After all adjustments are verified correct, possible cause of incorrect idle speed is deterioration of fast idle air control motor. Throttle valve must be replaced to correct symptom. Disconnect jumper wires and recheck idle speed.IDLE SPEED SPECIFICATIONS
Application Curb Idle Basic Idle 2.4L SOHC 650-850 10650-850 DOHC 700-900 700-900