Idle Speed Adjustments

Stop Screw Plug Removal:

NOTE: The throttle stop screw, which controls minimum idle speed, is adjusted at the factory and covered with a plug to discourage unnecessary adjustment. Normally, it should not be necessary to adjust unless the throttle body is replaced. A slow, unstable or fast idle is more likely caused by a NON-IAC system condition.

To gain access to the throttle stop screw, pierce the plug with an awl, and apply leverage as illustrated to remove the plug.

ADJUSTMENT:

1. Back idle stop screw out until there is an air gap between the screw and the throttle lever.
2. Turn the screw in until it just touches the throttle lever.
3. Turn the screw in an additional 1 1/2 turns.
4. Connect a scan tool to the ALDL connector.
5. Start engine and warm until normal operating temperature is reached
6. Momentarily disconnect and reconnect battery.
7. Observe "counts" on scan tool with all accessories "OFF." The ECM moves the IAC valve in small steps, called counts which are measured by the "Scan" tool.
8. With the engine stabilized, IAC valve position should be 10-20 counts. If not repeat procedure.,