Throttle valve is a controllable valve that controls the air entering the engine. When the gas enters the intake pipe, it will mix with the gasoline into a combustible mixture, which then burns to form work. It is connected to the air filter, the next engine block, known as the throat of a car engine.

Four-stroke throttle engine roughly like this. Throttle valve is one of the most important components of today's EFI car engine system, the upper part of it is the air filter [air grid], the lower part is the engine block, the throat of the car engine. Car acceleration is flexible, and the throttle has a lot of dirty, throttle cleaning can reduce fuel consumption but also make the engine flexible and dynamic.

Throttle has two kinds of traditional pull-line and electronic throttle, the traditional engine throttle control mechanism is through the cable (soft wire) or rod, one end connected to the accelerator pedal, the other end connected to the throttle interlock plate and work. Electronic throttle mainly through the throttle position sensor, according to the engine required energy to control the throttle opening angle, thereby regulating the size of the intake.