Firebird V8-305 5.0L (1982)
Vacuum Spark Delay Valve: Testing and Inspection
Distributor Vacuum Delay Valve (DVDV)
Distributor Vacuum Delay Valve
1. Connect a vacuum gauge to DTVS port of the valve and a hand operated vacuum pump to "CARB" port.
2. Apply vacuum. There should be a slight hesitation on the gauge reading. The gauge reading on the vacuum pump should drop slightly and balance
with the gauge reading at the TVS port. This should take about 3 to 4 seconds.
3. If there is no slight hesitation on the gauge readings, the valve should be replaced.
4. Remove gauge hose from DTVS port. Cover port and apply 15 inches Hg vacuum. The gauge,reading on the vacuum pump should hold steady. If
vacuum reading leaks down, replace the valve.
5. Uncover port and observe vacuum reading on gauge. Reading should drop slowly. If reading drops quickly to zero, replace the valve.
NOTE: Refer to the number stamped on the base of the switch or valve for calibrated switching or activation temperatures.
