See Figure 1
The EFE system is used on the 5.0L (VIN Y) engine to provide a source of rapid engine heat up during cold operations. It helps reduce the time that carburetor choking is required and helps reduce exhaust emissions.
The Vacuum Servo type consists of a valve, an actuator and a Thermal Vacuum Switch (TVS)-the valve is located in the exhaust manifold and the TVS switch is on the engine coolant housing.
A check of the operation should be made at regular maintenance intervals.
- With the engine cold, observe the position of the actuator arm. Start the engine. The arm should move toward the diaphragm (closing the valve).
- If the arm does not move, remove the hose and check for vacuum. If still no vacuum, remove the top hose from the TVS switch and check for vacuum.
- If vacuum is present in the top hose, replace the TVS switch.
- If vacuum is present at the actuator and it does not move, try to free the valve or replace the valve.
REMOVAL & INSTALLATION
- Disconnect the vacuum hose at the EFE.
- Remove exhaust pipe to manifold nuts.
- Remove the crossover pipe. Complete removal is not always necessary.
- Remove the EFE valve.
- To install, position the EFE valve into place.
- Install the crossover pipe.
- Install the exhaust pipe to manifold nuts.
- Connect the vacuum hose at the EFE.