Ok . My diag. shows the air inlet hose Ts to PCV breather hose . You can remove the air inlet hose at regulator valve and start the motor ( cold state ) , make sure you cap off the hose , then check to see if it has any suction . As engine warmed up , the valve should close ( no suction ) . Or , if you can look inside the valve , you can manually supply power and ground to it and watch the valve closes .