Description & Operation
The Vacuum Delay Valves (VDV) are used in the thermactor system with a catalyst to cutoff vacuum to the air bypass valve during deceleration.
These valves may be one-way or two-way delay valves, depending upon application. Although each valve is named for a given system, it may be used elsewhere.
NOTE:
Be sure valve is installed in correct direction, or engine will run rough, ping or use excessive fuel.