Fast Idle Speed

Fig. 4 Curb & fast idle speed adjustment. V8-379 engine:

V8-379 ENGINE

1. Apply parking brake, then block drive wheels.
2. Start engine and allow to reach normal operating temperature, then shut engine off.
3. Connect diesel tachometer J-26925 or equivalent, following tool manufacturer's instructions.
4. With air cleaner installed, start engine, then place transmission in Neutral on manual transmission models, in Drive on automatic transmission models.
5. Remove connector from fast idle solenoid and connect a suitable jumper wire between battery positive terminal and solenoid, Fig. 4.
6. Open throttle to ensure solenoid plunger is fully extended, then turn solenoid hex screw as necessary to set fast idle speed to specifications.
7. Remove jumper wire and reconnect solenoid electrical connector.