Bronco Full Size V8-302 5.0L (1986)
Vacuum Delay Valve: Description and Operation
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 below with an arrow to show the direction in which air flow is restricted (Fig. 1). Note that, although each valve is
named for a given system application, it may be used elsewhere.
