DESCRIPTION & OPERATION
Vacuum Delay Valves (VDV) are used on various parts of the engine to provide for gradual application or release of vacuum to engine or emission-related devices.
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.
TESTING
- Connect hand vacuum pump and hose to valve to be tested. Valves with both sides the same color are good if vacuum can be built up in both directions before bleeding off.
- Valves with one side Black or White and the other side colored, are good if vacuum can be built up in one direction only before bleeding off.
Note. Use care to prevent oil or dirt from entering valves during testing.
