Century V6-173 2.8L VIN W FI (1987)
Fuel Tank Pressure Release Valve: Description and Operation
PURPOSE
The Tank Pressure Release Valve (TPCV) valve allows fuel vapors to vent to the vapor canister. The valve provides vacuum relief to protect
against vacuum build up in the fuel tank and roll-over protection to prevent liquid fuel from entering the canister during normal driving maneuvers.
OPERATION
The evaporative check valve, a combination roll-over, integral pressure and vacuum relief valve, is located with the fuel sending unit in the fuel
tank. When vapor pressure in the tank exceeds 5 kPa (1 in. Hg) the valve opens and allows vapors to vent to the canister and then be purged. When
the tank pressure drops below the opening point of the valve it will close, keeping vapors in the fuel tank.