What is the reason for the rapid flameout at idle speed?

1. First, analyze the symptoms of idling flameout. If the engine will turn off as soon as it enters idle speed, we call it "no idle speed". The reasons for this failure are generally: the engine idle motor or the idle motor circuit is damaged; Brake vacuum booster vacuum tube leaks; Brake vacuum booster membrane is damaged; Air leakage in the intake manifold; There is a problem with the idle speed control module in the engine electronic control unit (ECU).

2. If the engine sometimes turns off when idling, and it is normal after restarting, we call it "intermittent idling flameout". This kind of fault is difficult to check for many reasons, and all kinds of parts or lines are not completely damaged. What's more troublesome is that the engine can return to normal after being turned off occasionally and then restarted. Therefore, even if the engine is idling due to the sensor, the engine electronic control unit will think that this phenomenon is not a fault and will not be recorded by the engine electronic control unit, so it is impossible to obtain information about the fault from the fault diagnosis system of the engine electronic control unit. The reasons for "intermittent idle flameout" are generally: the engine idle motor is stuck; The wire sheath of idle motor is somewhat worn; Idle air hole is too dirty; There is something wrong with the engine throttle position sensor; There is a problem with the camshaft position sensor or crankshaft position sensor; Engine speed sensor is faulty or too dirty; There is something wrong with the idling control program of the engine electronic control unit, and so on. In addition, if there is a problem with the quality of gasoline, it will also cause this failure.