Fast Idle Control Solenoid Valve
WARNING: This page is about a different car, the 1987 Acura Legend and 1986 Acura Legend. However, it is still accessible from the selected car via links, so may be relevant.
To prevent erratic running during engine warm-up, a higher idle speed is needed. When engine temperature is cold, this valve opens to by-pass additional air into intake manifold. This operation is dependent upon coolant temperature and atmospheric pressure.