Idle Air Control Valves
The idle air control valve is an electrically controlled valve that can vary the size of an air tube that leads to the throttle of a fuel injected system. The less air the throttle is exposed to, the lower the idle will be. So if the throttle has little air to deal with, the idle will be lowered. The engine control unit computer usually sends out the signals that control the idle air valve. These valves are only components of an electronically control fuel injection system and they are currently only in use in GM vehicles. If the valve is faulty, the idle may be too high or too low. There may also be problems with the signals the engine control is sending out. A common problem with idle air control valves is that they get very dirty. Sometimes, a good cleaning is enough to get rid of problems with this valve.