Firebird V8-305 5.0L (1982)
Vacuum Spark Delay Valve: Testing and Inspection
Distributor Spark VDV
OPERATION
This valve has two chambers with an orifice and one way check valve between them. This arrangement allows free air passage toward source
vacuum and restricted (delayed) air passage toward the controlled unit or units.
Ports 1 and 2 are connected to one chamber and connected to vacuum source. Ports 3 and 4 are connected to the other chamber and are subject to
the delay operation of the valve.
