See Figure 1
- Block the wheels and firmly apply parking brake.
- Run engine until normal operating temperature is reached.
- Place the vehicle in Park or Neutral, A/C in OFF position, and set parking brake.
- Remove air cleaner.
- Disconnect and plug decel throttle control kicker diaphragm vacuum hose.
- Connect a slave vacuum hose from an engine manifold vacuum source to the decel throttle control kicker.
- Run engine at approximately 2,500 rpm for 15 seconds, then release the throttle.
- If decel throttle control rpm is not within 50 rpm of specification, adjust the kicker.
- Disconnect the slave vacuum hose and allow engine to return to curb idle.
- Adjust curb idle, if necessary, using the curb idle adjusting screw.
- Rev the engine momentarily, recheck curb idle and adjust if necessary.
- Reconnect the decel throttle control vacuum hose to the diaphragm.
- Reinstall the air cleaner.
FUEL INJECTED ENGINES
These engines have idle speed controlled by the TFI-IV/EEC-IV system and no adjustment is possible.
6.9L AND 7.3L DIESEL ENGINES
Curb Idle Adjustment
See Figure 2
- Bring the engine up to normal operating temperature.
- Place the transmission in Neutral or Park. Firmly set the parking brake.
Idle speed is measured with manual transmission in Neutral and automatic transmission in Drive, with the wheels blocked and parking brake ON.
- Check the curb idle speed, using a magnetic pickup tachometer suitable for diesel engines. The part number of the Ford tachometer is Rotunda 99-0001. Adjust the idle speed to 600-700 rpm.
Always check the underhood emissions control information sticker for the latest idle and adjustment specifications.
- Place the transmission in Neutral or Park and momentarily speed up the engine. Allow the rpm to drop to idle and recheck the idle speed. Readjust if necessary.
- Start the engine and bring up to normal operating temperatures.
- Place the transmission in Neutral or Park.
- Disconnect the wire from the fast idle solenoid.
- Apply battery voltage to activate the solenoid plunger.
- Speed up the engine momentarily to set the plunger.
- The fast idle should be between 850-900 rpm. Adjust the fast idle by turning the solenoid plunger in or out.
- Speed up the engine momentarily and recheck the fast idle. Readjust if necessary.
- Remove the battery voltage from the solenoid and reconnect the solenoid wire.