Early Fuel Evaporation System: Description

The Early Fuel Evaporation (EFE) system is used on 5.0L 4-Bbl. (VIN Y) carbureted vehicles. EFE system provides heat to engine induction system during cold driveaway, providing rapid engine warm-up. System consists of a butterfly valve and vacuum actuator mounted between the exhaust manifold and the exhaust pipe, a vacuum tube and a coolant activated Thermal Vacuum Switch (TVS).