Thermostatic Air Cleaner: Description and Operation

Thermostatic Air Cleaner:

This system uses a thermostatically controlled air cleaner to maintain a predetermined air temperature entering the throttle body. This system is comprised of an exhaust manifold mounted heat stove, a heated air tube, an air temperature sensor, and a vacuum motor operated air valve.
The air valve in the air cleaner blends air warmed from the heat stove on the air cleaner with ambient (outside) air. The air valve can close the opening to warm or cold air, or blend a mixture of both.
The air valve in the air cleaner closes off the preheated air opening when vacuum is not applied to the vacuum motor.

Air Temperature Sensor:

When the engine is started, the temperature in the air cleaner is monitored by the air temperature sensor. If the air temperature is below the calibrated opening point of the sensor, vacuum will be applied to the vacuum motor to move the air valve towards the the ambient air opening and only warmed air from the heat stove will enter the air cleaner. As the exhaust manifold warms up and the temperature of the air entering the throttle body bonnet from the heat stove rises, the air temperature sensor begins to open and vacuum is bled off. This causes the air valve to start moving away from the ambient air opening towards the heat stove air opening. In this way, ambient air and heated air from the heat stove are blended for optimum engine performance and emission control.