Throttle value positioner
In general terms, the throttle valve must regulate the air or mixture supply for the combustion engine. Depending on the engine concept, this serves different purposes. In the case of petrol engines, speed and power output are regulated by means of fresh air or mixture dosing. Diesel engines generally do not need a throttle valve. However, in modern diesel cars, throttling the amount of intake air facilitates precision control for exhaust gas recirculation and stops the engine from shaking when the ignition is switched off.
The throttle valve is installed in the intake air system of the combustion engine. The opening angle of the valve determines how much fresh air or air/fuel mixture flows into the cylinders (carburettor engines, for example). In older generation engines, the throttle valve is connected directly to the accelerator pedal and operated mechanically via a cable.