Aerostar 2WD V6-245 4.0L (1990)
Vacuum Delay Valve: Description and Operation
Types Of Vacuum Delay Valves
Vacuum Delay Valves (VDV) are used for a gradual application or release of vacuum to a vacuum-operated device to help control emissions. The four
valves currently in use are illustrated with an arrow to show the direction in which airflow is restricted. Note that, although each valve is named for a
given system application, it may be used elsewhere.