Idle Speed: Adjustments

Fig. 2 Curb idle speed adjust. V6-182:

NOTE: Curb idle speed (RPM) is controlled by the Electronic Engine Controls (EEC-IV) processor and the idle speed control air bypass valve assembly. The throttle plate stop screw is factory set and does not directly control idle speed. Adjustment to this seting should be performed only as part of a full EEC-IV diagnosis of irregular idle conditions or idle speeds. Failure to accurately set the throttle plate stop position to the procedure below could result in erroneous idle speed control.

IDLE SPEED ADJUSTMENT
- Unplug Spark Output (SPOUT) connector and verify that ignition timing is 10 degrees BTDC (+/- 2).
- Remove PCV hose at the PCV valve and install 0.200 inch diameter orifice (Tool T86P-9600-A) or equivalent.
- Disconnect Idle Speed Control Air Bypass Solenoid.
- Place Automatic transmission in "DRIVE", manual transmission in "NEUTRAL".
- Check/Adjust idle rpm to 760 rpm (+/- 20), using throttle plate stop screw.
- Shut engine off and disconnect battery for 3 minutes minimum.
- With engine off, reconnect SPOUT connector.
- Remove orifice from PCV hose and reconnect to PCV valve.
- With engine off, reconnect idle speed control air bypass solenoid. Verify the throttle is not stuck in the bore and linkage is not preventing throttle from closing.
- Start engine and recheck idle speed.
- On automatic overdrive transmissions, check throttle valve pressure adjustment.