What is the reason why the car is shivering?

1, carbon deposit in the intake system, that is, there is a large amount of colloidal carbon deposit near the valve seat and around the idle motor, which leads to the mixture being too rich and too lean. Will form the phenomenon of idle jitter, especially when the cold car starts.

2. The throttle valve is too dirty, because there is too much colloidal carbon or dirt around the throttle valve plate, and the cross-sectional area of the air passage will change, which makes the control unit unable to accurately control the idle intake, resulting in the mixture being too rich or too thin.