Idle/Throttle Speed Control Unit: Adjustments

Idle Speed Adjustment:

Before checking and adjusting the idle speed, determine the following:

1. Spark plug wires and emission related vacuum hoses are connected securely.
2. Inspect the accelerator cable and verify that it is not binding or to tight.
3. Make sure all engine loads are "OFF."
4. Determine if the vehicle is in an area above an elevation of 8,200 feet (barometric pressure below 550 mm Hg). If so, the Idle Speed Control (ISC) valve will be operating and idle speed adjustment can not be performed.

Once the above has been performed, make sure that the engine is at normal operating temperature. Then, snap the throttle to determine that the idle adjusting screw is resting on its stop. Check the idle speed and compare it to the specified range on the engine decal, or see SPECIFICATIONS. Adjust the idle speed if necessary.