The automatic adjustment of the intake air temperature

Automatic temperature control is intended to improve fuel economy and reduce the content of hydrocarbons in the exhaust gases in the heating-up by maintaining the elevated temperature of the air entering the carburetor. Regulation of air inlet temperature will change the calibration data of the carburettor and the air damper in the direction of the depletion of the fuel mixture.

This system consists of a device with an adjustable bypass valve installed on the suction nozzle of the air filter and providing regulation of the ratio of cold and warm air directed into the carburetor. The damper device is changed by a vacuum diaphragm, which, in turn, force is transmitted from the temperature sensing element disposed within the air filter.

The system has a huge impact on the quality of the traction engine and emissions is in the first kilometers of driving with a cold engine.

On the cold engine valve device completely covers the suction channel of the air filter, while the carburetor comes only warm air, after flowing around the exhaust manifold. As the engine warms up and the flap is reopened through the suction pipe begins to act more and more cold air. When fully warm up the engine valve is opened fully, providing full access fresh cool air.

Automatic temperature control is intended only for supplying heated air to the engine is cold, so it is important to periodically check it in order to avoid disruption of the engine after warming up due to supply superheated or supercooled fuel mixture.

If the air filter flap sticks in position ?�no heat?�, the engine is unstable idling and stops before the full warm-up, so that the need to further depress the accelerator pedal. When valve is stuck in the position of ?�heat?� due to the constant flow of hot air into the carburetor will create the impression that the engine is not adjusted.

Technical condition

Checking the technical condition and maintenance, refer to the section. 2. If it is necessary to check if routine maintenance, act in accordance with the sequence shown below.

If the valve of the automatic temperature control is not completely cuts off the flow of cold air after a cold start, disconnect the hose from the vacuum suction nozzle aperture and attach the thumb to the opening of the hose. If there is a negative pressure supplied to the diaphragm, the reason for this may be freezing or sticking flaps and thrust inside the suction air filter. If there is a vacuum pump, apply vacuum at the damper actuator to make sure it is working after disconnecting regular vacuum hose. If the power of the vacuum pump does not cause valve opening temperature controller, and with proper connecting the vacuum hose valve opens freely, replace the vacuum diaphragm.

If in the above test, the vacuum on the diaphragm is missing, check the hoses for cracks, compression, as well as the reliability of their connections.

If the hose is not clogged and are in good condition, replace the temperature sensor located inside the air filter housing.

Replacing parts

Vacuum diaphragm air filter

Disconnect the vacuum hose from the diaphragm.

Remove the screw stopper, unhook and remove the diaphragm rod from the air filter housing.

When installing, enter the aperture in the air filter housing, screw it, attach the rod, screw the screw stopper.

Connect the vacuum hose.

Sensing element air filter

Remove the air filter to provide access to the space beneath.

Note the location of the vacuum hoses and disconnect them from the temperature sensor.

Carefully mark the position of the element, as exactly in this position should set a new item. Lift and remove the element from the air filter housing.

Install new element in exactly the same position as removed, attach the vacuum hoses.

Set the filter element and the top cover of the filter.