Air Control Valve A

Disconnect vacuum hose No. 15 (Prelude) from air control valve A and connect a vacuum pump. Disconnect the air hose between air control valve A and frequency solenoid valve A. Connect a hand vacuum pump and pressure gauge to the hose. See Figure .

Fig 1: View of Frequency Solenoid Valves Accord model shown; other models similar.
When vacuum is applied to vacuum hose side, air should flow without resistance and the pressure gauge should not register any pressure. When vacuum is released, air should flow with resistance and pressure should build up on gauge and be released gradually. If air control valve fails either test, replace it.

Fig 2: Checking Air Control Valves Accord model shown; other models similar.