Throttle valve — general information

The throttle valve is installed in the throttle body of the CFI assembly below the injector directly in front of the intake manifold and is connected to the accelerator pedal with a flexible cable.

Throttle sensor

Sensor (rotation potentiometer) throttle valve transmits information about the position of the throttle valve in the form of voltage signals to the EEC-IV device, which thus determines the engine operating modes:

• closed throttle for idle speed control;
• partially open throttle for normal engine load;
• wide open throttle for enrichment at full load or at startup;
• different degree of throttle opening for enrichment during acceleration.

Throttle control motor

This motor, mounted on the side of the injection unit, controls the final throttle position and thus the idle speed. Throttle valve idle position means for the EEC-IV device:

• at idle, the throttle motor controls the engine speed and keeps it constant. When the engine is loaded due to any consumer, the throttle motor receives a signal from the EEC-IV device to open the throttle until the idle speed stabilizes at a preset value;
• when decelerating, if the accelerator pedal is slightly released, or if the accelerator pedal is fully released, it enters the forced idle mode, the EEC-IV device, in accordance with the change in vacuum in the intake manifold, outputs a corresponding signal to the throttle motor.
• This signal prevents abrupt closing of the throttle valve and ensures that the throttle valve is closed gradually in accordance with the reduction in speed. As a result, the proportion of incompletely burned hydrocarbons in the exhaust gases decreases:
• when the engine is stopped, the EEC-IV device remains energized for 6 seconds thanks to the supply relay. As a result, the EEC-IV device has the ability to give a signal to the throttle motor to close it completely. After a while, the throttle motor opens it again. Due to such ventilation of the intake manifold, it is easier to start a warm engine;
• as soon as the engine is started again, the throttle motor moves it to the desired position. The current engine temperature is taken into account, so that you do not need to press the accelerator pedal when starting the engine.