Anti-Backfire Valve Test

Remove outlet hose from valve. Operate engine at a steady speed (approximately 1500 RPM), a steady flow of air should come from outlet. Remove vacuum hose from valve for a few seconds. Reconnect hose and check for a momentary stoppage of air flow from valve outlet and a momentary increase in air flow from ceramic silencer, indicating normal operation during a deceleration condition. If valve fails test, replace.