Ninety-Eight FWD V6-181 30L (1985) Early Fuel Evaporation (EFE) Description - Page 2741
Thermal Vacuum Valve: Description and Operation
Early Fuel Evaporation Thermal Vacuum Switch (EFE-TVS)
When engine coolant temperature is below the calibration point of the switch, manifold vacuum flows through ports 2 and 3 of this switch to the EFE
actuator, closing the EFE actuator. Above the switching point, port 3 of this switch is blocked and the EFE vacuum actuator is vented to atmosphere
through port 1.
