What is the reason why a car will stall if it doesn't loosen the throttle at idle speed?

There are many reasons for this failure, such as low fuel pressure, air filter blockage, fuel injector oil leakage atomization, improper idle speed adjustment, poor spark plug operation, air flowmeter failure and so on. The following is an introduction to relevant knowledge: 1. Causes of flameout: the fuel injector inside the engine leaks oil or is blocked, or the fuel injection quantity is small, so that the fuel can not be injected according to the instruction of the electronic control unit, which will cause the mixture inside the engine to be too thin or too rich, which will lead to the poor operation of individual cylinders of the engine and lead to the flameout of the engine. 2. Engine reason: We should also consider the problem of carbon deposition in the throttle. The function of the throttle valve is to control air in and out of the engine. After the air enters the engine, it will mix with gasoline to form a mixture to provide power for the engine. Throttle plays a very important role, just like the valve that controls air entering the engine.