Idle Speed: Adjustments

Refer to Specifications chart for curb and fast idle speeds.

Curb Idle Speed, Adjust

1. Place transmission into Park.
2. Start and allow engine to reach normal operating temperature, then turn ignition switch to OFF position.
3. Open cover on diagnostic connector and install adapter from dynamic timing gauge Rotunda tool 078-00116 or equivalent.
4. Start engine and check curb idle speed. If curb idle speed is not as specified, loosen idle speed screw locknut, then turn screw clockwise to increase engine speed or counterclockwise to decrease engine speed.
5. Momentarily increase engine speed and recheck idle speed adjust, if necessary.
6. After adjustment, check clearance between knurled knob on throttle advance cable and throttle lever. Gap should be .012-.028 inch (.3-.7 mm).

Fast Idle Speed, Adjust

1. Place transmission into Park.
2. Start and allow engine to reach normal operating temperature, then turn ignition switch to OFF position.
3. Measure and note distance between bracket and knurled knob.
4. Loosen thermostat housing bolts evenly until spring tension is released.
5. Again measure and note distance between bracket and knurled knob.
6. Subtract reading obtained in step 3 from reading obtained in step 5.
7. The difference should be .217 inch. If not rotate knurled knob until specified clearance is obtained.
8. Torque thermostat housing bolts to 11-14 ft. lbs.