How do I know that the throttle should be cleaned? How to know that the throttle should be cleaned?

The obvious feature of dirty throttle is unstable acceleration, which is big and small when idling, and the owner can directly feel it.

EFI car, as long as the engine is empty and neutral, slam on the accelerator pedal for 3000 revolutions, and then suddenly collect oil. Observe the pointer of the tachometer: if the pointer drops to about 800 rpm quickly and steadily, it means that the throttle valve is slightly dirty and does not need to be cleaned, which is basically normal. If the pointer quickly drops to below 800 rpm or even 700 rpm, and then slowly rises to around 800 rpm, and the idle speed changes from small to large, then the throttle valve has been seriously fouled and needs to be cleaned immediately.