Idle Speed/Throttle Actuator - Electronic: Testing and Inspection

Note; The idle speed on CIS-Motronic system is not adjustable. If the idle speed is not correct, then it is due to component failure, sensor error, or faulty wiring. The throttle bypass air screw should be turned in to its stop.
1. With the engine at normal operating temperature, idle speed should be 780 - 900 rpm.
2. With the A/C switched ON, the rpm should increase approximately 70 rpm.
3. If the speed values are not as specified, check:
a. Intake system for leaks (between the manifold and the throttle plate, and between the air flow sensor and the throttle plate).
b. Check the air flow sensor potentiometer, and adjust if necessary.
c. Check the wiring between:
1. The idle control valve and terminal 33 of the injection control unit.
2. The A/C relay and terminal 32 of the injection control unit.
3. Repair wiring as necessary.