Vacuum Delay Valve: Testing and Inspection

On-Vehicle Inspection
(a) Warm up the engine.





(b) With the engine idling, check that air suction is not felt at union pipe.





(c) Gradually increase the engine speed to 3,000 rpm, and check that there is air suction at the union pipe.
(d) Reconnect the EVAP hose to the union pipe.

Off-Vehicle Inspection




1. REMOVE VCV
Disconnect the 4 hoses from the VCV, and remove the TVV.
2. INSPECT VCV





(a) Apply vacuum above 9.3 kPa (70 mmHg, 2.76 in.Hg) to port S.
(b) Blow air into port Y, and check that air comes out of port Z.
(c) Release the applied vacuum.





(d) Blow air into port Y, and check that air does not come out of port Z.
If operation is not as specified, replace the VCV.
3. REINSTALL VCV
Connect the 4 hoses to the VCV.