Air Cleaner - Thermostatic: Description
All passenger cars are equipped with a system for preheating the air entering the carburetor or fuel injection unit.
This device maintains incoming air temperature at a point where the carburetor or fuel injection unit can be calibrated much leaner to reduce hydrocarbon (HC) emissions. It also improves warm-up operations and reduces carburetor icing.
This system consists of an air cleaner assembly, 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, cold weather modulators, vacuum check valves and vacuum delay valves.