Idle Speed

Engine idle speed is controlled by the ECU depending upon engine operating conditions and component/model application. The ECU senses engine operating conditions and determines the best idle speed. Basic idle speed is adjusted by changing the amount of air which by-passes the throttle plate via the Auxiliary Air Control (AAC) Valve.

The fast idle required for cold starts is accomplished through the use of an ECU controlled Fast Idle Control Device (FICD) and thermowax pellet fast idle cam.