E 250 Van L6-300 4.9L VIN E 1-bbl (1982)
Thermostatic Air Cleaner Vacuum Switch: Description and Operation
Auxiliary Air Inlet Valve
Fig.5 - Auxiliary Air Inlet Valve
The auxiliary air inlet valve is mounted on the outside of the air cleaner housing and serves to allow outside air to bypass the heated air inlet
system when the engine is under load. When manifold vacuum is low, a spring in the vacuum motor allows the valve to open, providing an
additional flow of air into the air cleaner housing, Fig. 5.
