General description
1. The intake air temperature control system provides warm air during engine warm-up and maintains the intake temperature at about 40 degrees Celsius. This improves the conditions for creating an optimal composition of the fuel-air mixture by the carburetor.
Pic. 11.1 Diagram of the intake air temperature control system
2. The balance between the amount of warm and cold air is provided by a damper in the air filter housing controlled by a diaphragm.
3. Warm air is taken from under the casing covering the exhaust manifold. When a sufficient engine temperature is reached, the sensor sends a signal to the control valve, which opens the vacuum to the diaphragm, and the damper switches the air intake.
Control
Note: the control is carried out on a switched off cold engine.
4. Check the integrity of all vacuum hoses serving the diaphragm.
5. Put the car on the parking brake and block the wheels.
6. Disconnect but do not remove the air filter housing (see chapter 4).
7. Rotate the air filter housing so that the damper is visible. It must be open. Otherwise, check the throttle for sticking. Move the damper by hand and check that there are no deviations.
8. If the damper moves freely and the vacuum control is insufficient, carefully inspect for leaks in the vacuum hoses. If no leaks are found, replace the diaphragm.
Replacement of system elements
9. Remove the diaphragm by turning it 90 degrees.
10. Installation is made in the return to removal order. Make sure the diaphragm rod is engaged with the shutter.