What Does an Idle Air Control Circuit Regulate?

• Posted on Autos.com Editor
• in Aftermarket Parts
• on October 7, 2013

The idle air control circuit is also called the off-idle circuit, and is adjusted with the wheels blocked, the vehicle in drive and the engine at normal curb idle. This adjustment allows an additional air adjustment to be made in order to smooth out the engine during idle while in gear. It is a circuit designed to ease the transition between idling and open throttle accelerations, by compensating for reduction in vacuum that is produced when the throttle is opened.

For more info, see Your Guide to Tuning Carbs