Why does my car idle rough then stall?

Why does my car idle rough then stall?

The fuel pump, which is responsible for pulling fuel from the gas tank to the fuel injectors, can become clogged or defective. If this happens the engine will not get enough fuel, which can cause a rough idle, sputtering, stalling and even slow acceleration. A rough idle is one symptom of a clogged fuel filter.

Why does my car stall when I stop sometimes?

If your car stalls when you come to a stop, it could simply be a dirty air filter. The air filter may have become so clogged that not enough air can pass through it to the engine. An air starvation problem in your engine could also be caused by a mass airflow sensor.

What causes engine to shut off while idling?

Faulty Oxygen or Mass Airflow Sensor Two of these sensors play a significant role in why a car engine stops while idling. Then your engine might not receive enough air, which it needs to power itself. When there’s a lack of air, it leads to a lack of power, which can cause your car to stall while idling.

What causes intermittent stalling in a car engine?

More Causes. One of the more unusual causes of intermittent stalling we’ve heard about is a defective vehicle speed sensor. When the vehicle stops moving, the PCM may not engage the idle speed motor (carbureted engines) or idle air bypass motor (fuel injected engines) so the engine will idle normally.

What do you need to know about intermittent stalling?

And if there are no pending codes, hard codes or history codes in the vehicle’s computer to give you some direction, you may find yourself guessing at a diagnosis. Every engine needs three things to run and idle smoothly without stalling: a correct air/fuel ratio, sufficient idle speed for the idle load, and a good spark.

Why does my car idle rough when at a stop?

Hello. Typically, if this vehicle runs fine at all other times and will have trouble idling when coming to a stop, it is almost always caused by a bad idle control valve. Most of the time the valve fails making it impossible for the computer to adjust the idle to the correct level.

What to do when engine stall Idle Stop?

Aim for the little air bypass holes in the throttle opening. Use the small plastic tube that attaches to the nozzle on the aerosol can to aim the cleaner directly into the bypass port (s). Let the cleaner soak for at least 10 minutes before giving it another blast of cleaner.