Emission Control Systems: Adjustments

Idle Speed Setting:

1. Unplug spout line and verify that ignition timing is base +/- 2 BTDC (refer to decal).
2. Disconnect idle speed control-air bypass solenoid.
3. With transmission in Neutral or Park:

Run engine at: 2500 rpm/30 seconds

4. Place automatic transmission in Park manual transmission in Neutral.
5. Check/adjust idle rpm:
Turn the throttle plate stop screw to 550-600 rpm.
6. Reconnect spot line.
7. Engine off reconnect idle speed control-air bypass solenoid, verify the throttle is not stuck in the bore and linkage not preventing throttle from closing.
8. Start engine and stabilize for 2 minutes then goose engine and let it return to idle, lightly depress and release the accelerator. Let engine idle, if idle problem still exists, refer to COMPUTER ENGINE CONTROLS/DIAGNOSTIC ROUTINES for other possible causes.