Early Fuel Evaporation System: Operation
During cold engine operation, less than 105°F (40°C), manifold vacuum is routed to the EFE vacuum motor through the TVS, closing the EFE butterfly valve. This routes all exhaust gases from that side of the engine through a special crossover passage in the intake manifold, below the carburetor. This results in faster fuel evaporation, more uniform fuel distribution, faster choke opening and reduced emissions.