Minimum Air Rate - Fuel Injection Only

CHECKING MINIMUM IDLE SPEED

NOTE: A base RPM adjustment is not normally required and should not be perfomed unless the base idle stop screw had inadvertenly been misadjusted during servicing.

1. Select ECM override "ES03" ISC MOTOR. (See COMPUTERIZED ENGINE CONTROLS)
2. Press the COOLER button on the CCDIC (Climate Control Driver Information Center) display panel to retract the ISC motor. The ISC motor will slowly retract. Verify that the throttle lever is resting on the minimum idle speed screw. If the engine stalls, go to step 5.
3. With the ISC fully retracted, the plunger should not be touching the throttle lever. If contact is noted, adjust the ISC plunger so that it is not touching. Make sure that the throttle is not being held by the throttle, cruise, or transmission cables.
4. Check the minimum idle speed using ECM data parameter ED11, "ENGINE RPM". If the minimum idle speed is not within specifications (see MECHANICAL SPECIFICATIONS under SPECIFICATIONS), go to step 5.
5. Check the primary throttle blades for deposits that might restrict air flow. If there are deposits, clean the primary throttle bore and the area behind and around the throttle plate using a clean shop towel with top engine cleaner or equivalent. Do not use any solvent that contains METHYL ETHYL KEYTONE. Return to step (1) after cleaning the throttle body.

NOTE: If engine speed is too high, check for vacuum leaks. If the minimum air setting is made with a vacuum leak present, fuel control can be adversely affected throughout all driving conditions.

IF ADJUSTMENT IS NECESSARY:

6. If the minimum idle speed is out of limits, adjust the idle screw using a T-20 torx driver to specifications. See MECHANICAL SPECIFICATIONS under SPECIFICATIONS.