What Causes a Car to Stall While Accelerating

What causes a car to stall while accelerating? Well, the most common reasons are moisture in the distributor cap, a vacuum leak, or a bad throttle position sensor, however, whatever the reason is, it will all depend on the condition on how the problem of stalling occurs, is the stalling happens on cold rainy mornings, is the stalling is gradually becoming frequent or is the car stall at any engine temperature. Different conditions have different reasons why the problem of stalling especially while accelerating happened.

The reason why cars stall while accelerating

(1) Moisture in the distributor cap.
(2) Vacuum leak.
(3) Bad throttle position sensor.

Car troubleshooting

If the stalling typically happened on a cold wet morning with the engine is cold, then the problem is moisture in the distributor cap causing misfiring. As mentioned above, the stalling problem typically occurs on cold, wet mornings, and when the engine is cold. What is probably going on here in this situation is the following.

During the night, condensation (i.e. moisture) forms inside the distributor cap, it is due to the cold and wet weather and, the fact that the engine is cold. The moisture often allows electrical current to arc inside the distributor cap, resulting in "engine misfire". As it turns out, this arcing is most extreme during acceleration and therefore it causes the engine to misfire so severely, it (the engine) stalls.

What will you do?

The next time you expect rain or any other wet weather coming, park the car inside the garage for the night. This should help prevent moisture from forming inside the distributor cap. However, if this is not typically occurring on cold mornings with a cold engine, then rule out moisture in the distributor cap as the cause of the problem.

If the problem has become more frequent over time then a vacuum leak is possible. As indicated, the stalling problem gradually became more frequent over time. This suggests a "vacuum leak" as being the culprit since vacuum leaks typically start out small and gradually (over time) become worse due to pressure inside the engine.

At this point, you may be wondering what all this "vacuum" stuff is about. Well, it is very difficult for a non-mechanic to properly understand this. Therefore, all that we can be offered is the following simple explanation. The vacuum created in a car's fuel system is one of the key factors in determining how much fuel an engine will get. Any leak in a fuel system's vacuum will intermittently throw off the air/fuel mixture that enters the engine's combustion chambers. Consequently, this results in engine hesitation at the very least or, as in the case of this vehicle, stalling.

What will you do?

Please take the car to a garage and ask the mechanic to check for a vacuum leak. In particular, have the mechanic check both the EGR and PCV valves since these are items that are often found to be the source of vacuum leaks. When talking with the mechanic, describe to him exactly what this article explained to you. Why? Because it's always important to exhibit some knowledge of the problem.

Cartechhome recommends finding a garage that is approved by the AAA. Such garages tend to be fairly reputable and, best of all, if you have a dispute after any work is done, the AAA has the policy to investigate the situation and resolve it.

Now, if the problem does not become more frequent then rule out the vacuum leak as the problem but rather it's a bad throttle position sensor that causing the problem.

First off, for a car that has fuel injection and the stalling problem DID NOT "gradually become more frequent over time". This implies that the severity of this problem has likely remained constant throughout. Because of this, a probable cause of this problem is a "bad throttle position sensor". Let's look at this a little closer.

Fuel-injected engines have a "throttle position sensor". This is a device that measures how far the driver has depressed the gas pedal (and thus the throttle). The throttle position sensor feeds its data to the engine's computer which in turn makes a calculation. The result of this calculation is used to determine precisely how much gas the fuel injection system should "inject" into the engine (at that instant).

Now, if the throttle position sensor provides the wrong data to the engine computer it will adversely affect the injection of gas that goes into the engine and it will result in a problem. Clearly then, a faulty throttle position sensor will adversely affect the injection of gas into the engine, often resulted in car stalling during acceleration.

What will you do?

Take the car to a garage and have the mechanic check the throttle position sensor. Tell the mechanic exactly what we talked about in the explanation for this diagnosis. This is very important in that it shows you know something about the nature of this stalling problem.

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