What is the sound of air spouting from the accelerator when the car is idling?

When idling, the engine is adjusted according to the engine speed, and the torque output of the engine is controlled through the gas path and the fire path, so that the engine speed is controlled within the preset speed range. The adjustment of the air passage is adjusted by the size of the throttle valve. When the idle speed is unstable, the throttle will keep shaking, so its intake air volume will also fluctuate.