Why Does My Car Turn Off When I Stop

Why Does My Car Turn Off When I Stop

Have you ever been driving or while stopped and the car shuts off randomly? If this has happened to you, then it is possible to wonder what could be the problem.

A number of things could be culprits starting with the fuel pump, no gas, faulty throttle body, and many other things. Sometimes it could be that your car has a start-stop feature or you just do not know how to drive a manual.

We shall look at the various reasons why you might be experiencing this problem and which would be the best way to deal with them. Let us get into the guide already.

Start-stop feature

Newer car models now come with a start-stop feature installed. The aim of this feature is to save you fuel each time you stop.

The feature turns off the car when you stop let us say in traffic and would turn on the engine the next time you depress the gas pedal.

It can be a good feature, but sometimes it can catch you off guard thinking there is something wrong with the car.

You have the option of turning off the feature so that your car does not turn off the engine each time.

Faulty fuel pump

An engine would shut off if there is no fuel reaching it. This mostly happens when the fuel pump is faulty.

Most cars would have a whirling sound each time you put the key to the ON position in the ignition. That is the fuel pump getting ready to send fuel. If your car no longer does that, it could be the fuel pump is faulty.

As much as it is not harmful to drive with a faulty fuel pump, it can stop working at any time. Thus the reason you should have it checked and replaced as soon as possible.

Here is a video on diagnosing a faulty fuel pump.

Other fuel-related problems

The reason your vehicle turns off when you stop could also be related to many other fuel-centered problems.

An example is that you could just be out of fuel. It does not come as a surprise as some people would ignore the fuel indicator light telling them it is time to fuel again. If you do not fuel it, the car eventually turns off for lack of fuel.

Sometimes you could have a faulty fuel gauge. So, make sure it is repaired so that you always know when to fuel the car to avoid such scenarios.

A dirty fuel filter and injectors could make the car shut down on its own. Whenever the filter or injectors are clogged, it means that the engine does not receive enough fuel. This can make the car stall or decline to start.

Air delivery issues

Having a faulty throttle body would make the engine run roughly and also shut down because there is not enough air getting to the combustion chambers.

The engine needs proper airflow to have the right air-to-fuel ratio. When the throttle body seems not to be opening, then the engine is choked.

You can also look at the throttle position sensor. If the sensor is not working, it is best to have it replaced for good performance. It is this sensor that would tell the ECU how much fuel to send to the engine. If it is damaged, then there is no fuel thus the engine stalls.

Something as simple as an air filter could make the car stall also. This is because there is not enough clean air getting to the engine. That is why you have to change it more often to avoid a car that does not run smoothly or can stop anytime.

Air filters are quite cheap so there is no reason not to change them during your next service.

Here is a video with details on how you can lose power with a clogged air filter

Engine sensor issues

Having a faulty crankshaft position sensor is something you would not want. This is because, without it, the ECU would not know when to control the spark and would be out of timing for ignition and fuel flow.

The best way to know if it is the issue, plug the car into a car’s diagnostics machine. It would tell you more about why the car is not starting. If the crankshaft sensor is the issue, then it is best to replace it.

The diagnostics report may also show that you have a faulty mass airflow sensor. This is what helps control how much air goes into the engine to avoid rough idling or stalling while stopped or driving.

Common symptoms of a bad MAF sensor are when the idle speed increases erratically, the fuel consumption is higher, and the car also surges erratically.

A faulty ECU

The ECU is like the brain of the engine so if it is not working, then the engine will not run thus you end up with a car that stops at any time even while not driving.

An example is when the engine needs the fan to do the cooling, but the sensor that needs to send the signal cannot find the ECU, then the fan would not turn on. This means that you end up with a car that overheats even when not driving.

So, you can have a proper mechanic test the ECU and find out if it is still working or if it should be replaced. If it seems to have issues, then buy a new ECU than repairing the old one.

Faulty alternator

The job of the alternator is to charge the car’s battery. If it is not working as expected, then the car would drain the battery fast and turn off since there is not enough power to keep the engine running.

One mistake people do is to add so many electrical devices to one battery. This would mean the battery is strained and can easily die from overload. Also, if you have an old battery, it might not be holding charge even if the alternator is working.

So, test the alternator first to see if it is working and then check the battery too. Using a battery tester can help you know if it is the battery or alternator that has an issue.

Here is a video on how to test a car battery with a multimeter


What should you do if the car suddenly turns off?

Try starting the car again to see if it cranks or not. In case it cranks, it can mean the battery is low. However, if it does not, it could mean that there is a serious problem and you need more assistance from a mechanic.

Can a bad catalytic converter make the engine stop running?

When the catalytic converter is already too clogged, the car would not run as smoothly as you want. It is possible for the exhaust gases to back up into the engine making it overwork or stall.

How do the engine mounts make the car turn off?

If the engine is not secured to the chassis properly, the excess vibrations can make it break something. So, the engine would stop working because there is component damage. Always make sure the engine mounts are in great condition.

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