What is the reason for the idle jitter of hot cars?

Reasons for idle jitter of hot cars: 1, the most common ones are dirty throttle or faulty throttle, which will lead to idle jitter of hot cars; 2. The main reason of dirty throttle is that there is carbon deposit on the shaft at the joint of throttle plate and throttle body, which leads to inaccurate throttle opening, so the idle speed will shake; So we can clean the next throttle first. If it doesn't shake after cleaning, it means the throttle is dirty. If it still shakes, it means that the accelerator is out of order and needs to be tested in the repair shop.