C 20 3/4 Ton Pickup 2WD V8-305 5.0L VIN H 4-bbl (1982)
Thermal Vacuum Valve: Description and Operation
EGR Canister Purge Thermal Vacuum Switch (EGR-CP-DTVS)
EGR Canister Purge Thermal Vacuum Switch (EGR-CP-TVS)
When engine coolant temperature is below the calibration point of the switch, ported vacuum is blocked from the canister and the EGR valve.
Above the switching point, ported vacuum is directed to both the canister purge port and the EGR valve.
