What should I do when the Elantra hot car is idling?

Hello! Regarding the problem of unstable idle speed of the hot car you consulted, the main fault reason is the increase of carbon deposition in throttle, air inlet and valve. When the car is cold, it absorbs some gasoline, and when it is hot, it volatilizes, which will cause the mixture to be too rich when the engine is idling, which will lead to the unstable idling of the hot car. So you should check whether there is too much carbon and dirt on the throttle and air intake. If it is too much, the cross-sectional area of the airway will change, which will make the control unit unable to accurately control the idle intake, resulting in too rich or too lean mixture, which will cause abnormal combustion or engine jitter or even failure to start after starting. Also pay attention to whether the carbon canister is faulty.