Parisienne V6-262 4.3L (1986)
Vacuum Check Valve: Description and Operation
Early Fuel Evaporation Check Valve (EFE-CV)
This valve is located in the vacuum line from the carburetor to the EFE thermal vacuum switch. The EFE-CV holds the highest vacuum reached,
enabling the EFE heat valve to remain closed until the TVS switches modes. It also prevents the heat valve from rattling during severe low vacuum
conditions (heavy acceleration).