Air Cleaner - Thermostatic: Description
All passenger cars are equipped with a system for preheating the air entering the carburetor or the fuel injection unit during cold engine operation.
This system maintains incoming air temperature to a point where the carburetor or fuel injection system can be kept lean to reduce hydrocarbon (HC) emissions, and reduces carburetor icing.
This system consists of an air cleaner assembly with integral air control door, vacuum control temperature sensor, vacuum motor, heat shroud (on exhaust manifold), heated air tube and vacuum hoses. Some models also use additional controls such as vacuum traps and cold weather modulators.