Base Idle Speed

The minimum idle speed air rate is set at the factory with a stop screw and is not adjustable. This setting allows enough air flow by the throttle valves to cause the Idle Air Control (IAC) valve pintle to be positioned a calibrated number of steps (counts), from the seat, during controlled idle operation. If Idle Speed is incorrect, begin diagnosis at Powertrain Management / System Diagnosis / Flow of Diagnosis. Testing and Inspection