The throttle plug of the car is broken.

Causes of loose harness of throttle plug, unstable idle speed, inability to refuel and throttle failure; Too dirty throttle or too much carbon deposit on fuel injector, gear start-up jitter, cold start, insufficient three-way catalytic temperature and serious carbon deposit on engine are the most common reasons for automobile jitter, because gasoline adsorbed on carbon deposit after landing is sucked into cylinder by engine for combustion, and the combustible mixture of engine is sometimes rare and thick, which leads to idling jitter after cold start. Solution: The company cleans the oil circuit, and checks whether the idle motor has carbon deposit, so it should be cleaned.