Why does the idle speed become higher after starting the car in summer after being exposed to the sun?

[DelVincent]

Here are the reasons why the idle speed becomes higher after starting the car in summer after being exposed to the sun: 1. The greater the temperature difference, the higher the speed: It is normal for the idle speed to be higher when starting. The car needs a high speed to allow the engine to reach normal working conditions as soon as possible, requiring a richer mixture, so the intake air volume and fuel injection volume will increase, resulting in a higher speed. To save fuel and reduce wear during startup, there is generally a cold fast idle or water temperature sensor. The colder the weather, the lower the water temperature (compared to the normal working temperature of the engine, generally around 85-110 degrees), that is, the greater the temperature difference with the normal engine working temperature, the computer will control the higher the cold fast idle speed, which means the higher the engine speed when just starting. 2. Excessive carbon deposits: A high speed is generally caused by excessive carbon deposits. Timely cleaning of the throttle and idle motor can generally solve the problem.