Ranger 2WD V6-245 4.0L (1990)
Idle Speed: Adjustments
Idle Speed Setting
1.
Disconnect idle speed control-air bypass solenoid.
2.
With transmission in Neutral or Park, run engine at 2500 rpm/30 seconds
3.
Place automatic transmission in Park manual transmission in Neutral.
4.
Check/adjust idle rpm:
Turn the throttle plate stop screw to 675 rpm.
5.
Shut engine off and repeat Steps 2, 3, and 4.
6.
Shut engine off and disconnect battery for a minimum of 5 minutes.
7.
Engine off reconnect idle speed control-air bypass solenoid, verify the throttle is not stuck in the bore and linkage not preventing throttle from
closing.
8.
Start engine and stabilize for 2 minutes then goose engine and let it return to idle, lightly depress and release the accelerator. Let engine idle,
if problem exists, refer to COMPUTER ENGINE CONTROLS/DIAGNOSTIC ROUTINES for other possible causes.