回复：今天在红灯停下，结果发动机熄火了

your car stalls out at red lights, it means that your engine suddenly can’t control the idle.  When your engine loses the ability to control the idle, this could be due to several factors, including the following:

• A malfunctioning or dirty mass air flow sensor.  We’ve mentioned before in this blog that your car contains a large number of sensors that send information to your car’s computer.  The mass air flow sensor monitors the quality and quantity of air passing into the engine, which lets your engine know how much fuel to use.  If the sensor is dirty or not working properly, then it will send incorrect information to the engine and cause your car to stall out when idle.  In such a case, cleaning or replacing the mass air flow sensor can fix the problem.

• A clogged or malfunctioning idle air control valve.  The idle air control valve is an important air regulator in your vehicle because it allows only the perfect amount of air into your engine to keep it running properly.  However, carbon can build up on the valve and keep it from letting the correct amount of air through or the valve can simply malfunction.  When either of these problems occurs, your car can begin to stall when idle.  The valve may need to be cleaned or replaced in order for your car to work well again. 

• The spark plugs are worn out.  Your spark plugs are responsible for sending electric currents to your car’s engine from the ignition.  If the plugs and their wires are worn out, this can cause a disruption in the flow of electric currents and make your car want to stall or even misfire.  It would be a good idea to get your spark plugs and wires replaced as soon as possible, if this is the case.