FREE REPAIR MANUALS & LABOR GUIDES 1982-2013 Vehicles
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Thermal Vacuum Valve - EVAP: Description and Operation

PURPOSE
Controls when canister purge happens.

LOCATION
In coolant passage of the intake manifold.

OPERATION
The two TVS ports are connected to the vacuum hose between the canister and TBI unit. When engine temperature is below 46° C (115° F), the TVS is closed and prevents canister purge. The TVS opens above 46° C (115° F), allowing canister purge