Idle Speed Control

Idle Speed Control

With the throttle pedal released and the engine at idle, the ECM maintains stable idling performance by using the fast response of the engine to changes in ignition timing. According to the loads placed on or removed from the engine, the ECM responds to changes in engine speed and, together with adjustments to the idle air control valve (IACV), advances or retards the ignition timing to achieve a constant idling speed. When load is removed from the engine, the IACV returns to its original position and the ignition timing reverts to the idle setting

NOTE: Due to the sensitivity of this system the ignition timing will be constantly changing at idle speed.