Throttling action

The main function of the throttle valve is to control the air intake according to the load of the engine. Throttle is a device on the engine intake system, which is a circular steel plate with a shaft in the middle and controlled by throttle cable. Therefore, when we step on the accelerator, we actually increase the air intake, not the fuel supply. When the air intake increases, the computer will instruct the fuel injector to increase the fuel supply. When the engine is running at low speed, due to the small throttle opening and the small air intake (flow), some extremely fine dust (not filtered by the air filter) and exhaust gas in the engine valve chamber will be deposited on the throttle and the air intake of the idle speed control valve, resulting in the problems of slow throttle response (reduced actual air intake) and unstable idle speed.