Your car shutting off when you stop it or are slowing down can be annoying and dangerous.
If you notice that your car works just fine at high speed but shuts off as soon as you start to slow down or when your vehicle comes to a halt, there is a specific problem.
To resolve the issue, you first need to get to its cause, as it could range from a broken fuel pump to just a clogged ERG valve.
It would be best if you tried to get to the cause of it right away so you can resolve it to prevent any damage to your beloved car.
Here are some reasons why a car shuts off when stopped or slowing down:
Broken Fuel Pump
The fuel pump is responsible for transferring fuel from the fuel tank to the engine when you start and run your car.
Not only can a broken fuel pump be the reason behind performance issues, but it can also lead to your car shutting off when stopped or slowing down.
A broken fuel pump results in low fuel pressure, causing inconsistent fuel flow to your engine. It does not make much difference at high speeds, but at low speeds, this could be causing your car to shut off.
It is not safe to drive your car with a broken fuel pump. Furthermore, other indicators will help you narrow down whether or not the cause of your problem is a failed fuel pump.
These include reduced gas mileage, whining noise from the fuel tank, and trouble starting the car.
An ignition system in a car produces the spark that ignites the fuel-air mixture to start and run the vehicle. If your ignition system is firing inconsistently, it can cause your engine to stall.
It could explain why your car shuts off when stopped or slowed down. Some wires, known as the ignition wires or the spark plug wires, are part of the ignition system circuit.
The connection of these wires needs to be consistent and constant for the ignition system to function correctly. If these wires are loose, damaged, or corroded, it may cause problems.
Among these is the ignition wire, which supplies the spark plug with voltage.
Damage to the wire would thus cause the engine to lose voltage, and the power to create the spark to ignite the fuel would be insufficient. It would explain why your vehicle is shutting off.
Worn Out Spark Plugs
Spark plugs are responsible for creating the spark and igniting the air-fuel mixture inside the combustion chamber to start the car and get it moving.
If your spark plugs are old and worn out, they may not be effective at creating this spark. It would disrupt the current flow.
It would explain why your car shuts off when stopped or slowing down. Other signs of faulty spark plugs include slow acceleration, poor fuel economy, engine misfiring, and engine surging.
It is suggested to equip your car with good quality spark plugs to prevent them from wearing out too quickly.
The five types of spark plugs available on the market are copper, silver, iridium, single platinum, and double platinum.
Copper spark plugs do not last too long but are relatively affordable. While the rest of the spark plugs are expensive, they last nearly ten times as long as copper spark plugs.
Transmission Problems can happen due to the torque converter in your car. The torque converter connects the power source to the rotating driven load in an automatic transmission car.
It uses fluid to pass the power to the transmission. It prevents your engine from stalling and allows the transmission to change.
If your torque converter is damaged or faulty due to other reasons or the fluid level in the transmission is low, the power will be inconsistent at low speeds.
It would explain why your car shuts off when stopped or slowing down. If your torque converter is damaged, you should immediately tend to it.
A bad torque converter can be harmful to your engine in several ways. It can cause overheating, friction, and transmission fluid degradation.
Problems can also occur if your transmission fluid is contaminated.
Faulty Fuel Injectors
Faulty fuel injectors are another cause that can explain why your car shuts off when stopped or slowing down.
Fuel injectors are responsible for spraying some fuel when the spark plugs create a spark to ignite the fuel. If the fuel injectors are faulty, it will result in a low fuel pressure or lack of this fuel at slow speeds.
As a result, insufficient power would be generated at low speeds. It could explain why your car shuts off when stopped or slowing down.
Other symptoms of faulty fuel injectors include engine misfires, poor gas mileage, inconsistency at the RPM needle, and even car not starting.
Often, the fuel injectors malfunction when they are clogged. It requires concentrated cleaning to unclog the injectors.
Concentrated cleaner products are mixed with water for this purpose. Cleaners specifically for cleaning fuel injectors are also available.
Faulty EGR Valve
EGR stands for Exhaust Gas Recirculation. It is responsible for recirculating a small amount of exhaust back into the combustion chambers to decrease their temperature.
Since exhaust gas comprises carbon dioxide rather than oxygen, it decreases the combustion rate and thereby brings down the temperature. A faulty EGR valve is usually clogged.
As a result of getting clogged, it gets stuck open or close and prevents the exhaust gas from flowing back into the combustion chambers.
It affects the air to fuel ratio inside the combustion chamber and leads to loss of power. As a result, your car shuts off when stopped or slowing down.
If your EGR valve is clogged, you do not necessarily have to replace it. Rather than that, you can clean it.
The EGR valve is usually clogged with carbon deposits so, you will have to watch for them.
EGR valve cleaners are available, which you may spray onto the carbon build-up and then clean with a pipe cleaning brush.
Next, wipe the surface with a piece of cloth. If the valve is hard to clean, you may need to soak it in the cleaning solution for a few minutes.
Once you have figured out why your car is acting the way it is, you can easily find a suitable solution for it.
If you are not a car expert, a visit to your mechanic will usually help you resolve your issue.
However, it is advised to tend to it as soon as possible, as some of these causes can cause severe damage to your car if left untreated.
With comprehensive experience in writing exceptional quality articles and blogs about cars and related stuff, Daniel is one of the finest bloggers and a hardcore car lover we have. He is an ASE certified technician with an across-the-board experience of 10 years in the industry. He could not help tinkering with anything he got his hands on from a young age, which led to his remarkable career in the automotive repair industry.
When he is not under any hood, you can find him on the water or in the woods to pursue his passion for hunting and fishing. He has been writing for multiple sectors and is a regular contributor to several publications.
He currently owns a Nissan 300ZX TT and a Pearl Yellow but plans to upgrade it to 550 HP. His favorites include the Koenigsegg CCX and Lamborghini Diablo 6.0 VT, but for him, the Ferrari 360 Spider is one of the sexiest cars that exists to date.
Being an avid world traveler, he has spent most of his time analyzing the automotive markets, latest technology, and local favorites to enhance his knowledge base. He is currently living in North Caroline, where it’s all about food and coffee and, of course, cars.