Repair Pontiac Mid-size 1974-1983 Repair Guide

Early Fuel Evaporation (EFE) System

Imprimir

OPERATION





Click image to see an enlarged view

Fig. Fig. 1 Exploded view of the vacuum servo-type EFE system



Click image to see an enlarged view

Fig. Fig. 2 EFE system component mounting-V6 engine shown



Click image to see an enlarged view

Fig. Fig. 3 The electric EFE heater plate is located under the carburetor

Two types of EFE have been used on the engines covered in this guide. Both provide quick heat to the induction system, which helps evaporate fuel (reducing emissions) when the engine is cold and aids cold driveability. The Vacuum Servo EFE system uses a valve between the exhaust manifold and exhaust pipe, operated by vacuum and controlled by either a thermal vacuum valve or electric solenoid. The valve causes hot exhaust gas to enter the intake manifold heat riser passages, heating the incoming fuel mixture. The Heated-type EFE uses a ceramic heater plate located under the carburetor, controlled through the ECM. The vacuum-type EFE should be checked for proper operation at every tune-up.

On 1981 and later V6 engines, the EFE system