The fuel pump is probably the most important part of your vehicle. Its function is to take gas from the tank and send it to the engine. It allows your car to start and run. Because it is such an important part, fuel pumps should last you for at least 100,000 miles.
Summary
The most common symptoms of a weak, failing, or bad fuel pump are the check engine light coming on and the engine misfiring. However, other signs of a failing fuel pump are reduced power and weird acceleration.
In this article, we’ll also cover the following:
- What makes it go bad
- What happens when it goes bad
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If you have already exceeded the 100,000-mile mark, there is a high chance of the fuel pump failing. When that happens, there are specific symptoms you can look for and take the necessary action to replace this component. The fuel delivery system is complex, and such an important part has to be highly valued.
For modern cars, this part is considered to be their heart. Once this pump fails, the entire vehicle will stop running, and you might also have trouble starting it up again. This article will look at 12 bad, failing & weak fuel pump symptoms so you can make troubleshooting easier.
Table of Contents
What does a fuel pump do?
This part sends gas directly to the engine, which makes it a vital part of your vehicle. This process is simple but essential. The gasoline will pass through a fuel filter to reach the injectors and finish by combusting inside the cylinders.
Without this pump, fuel would have no way to reach the engine, and the pistons would have difficulty delivering power. In some older vehicles, mechanical fuel pumps use complex diaphragms to transport the fuel to the engine.
Modern cars have electric fuel pumps mounted inside the gas tank. These ones are also safer because they reduce fire risk. Since they are installed far from the engine, they often work independently.
If this part is failing, it is crucial to change it as soon as possible, as your vehicle might represent a real danger for other drivers. Your car will not work properly without this component.
Symptoms of a bad, failing, & weak fuel pump
There are several symptoms that will tell you if the fuel pump is bad, failing, or weak. We found the most common 12 ones, so pay attention and notice if you can identify some of them in your vehicle.
Let’s take a look at some of the signs:
- Increased fuel consumption
- Loss of power
- Fluctuating engine speed
1. The check engine light comes on.
This light will appear on your dashboard once you have fuel pump issues. Most likely, your car has already started running weirdly. It lacks the smoothness you were used to.
Use the check engine light as a final confirmation that something is wrong with the component. A specialized mechanic will be able to diagnose your vehicle and recommend replacement parts.
2.Increased fuel consumption
When this component is failing, the engine might consume more fuel. You should notice this after driving for a while. You will know the difference between your average consumption and the new one.
In this case, you might want to check the entire fuel system. Take your car to an auto repair shop and have the experts take a look at it.
3. The car struggles to climb a hill.
If you live in an area with hills, you are most likely used to having your car climb them effortlessly. When this part is failing, the entire performance of your car is reduced. You will notice this, especially when you are driving uphill.
4. Reduced power
Because there is not enough gas supplied to the engine, the power will be reduced. It means you might lose the ability to reach and maintain a stable high speed. On a highway, this can be dangerous.
Pull over to the side and call for help, as your vehicle is now a danger to other drivers.
5. Engine speed fluctuates
Because the gas delivery is uneven, the performance of your engine will fluctuate. The car will want to accelerate and slow down shortly after while constantly repeating this cycle. On a highway, it can be extremely dangerous.
6. Acceleration is hesitant
Under normal circumstances, your car should be able to accelerate quickly from a full stop. An instant response is necessary, especially on a busy street or when you merge into traffic.
But if your fuel pump is failing, you might experience a delayed response when you step on the gas.
7. The engine is misfiring.
Often, you will feel misfires rather than hear them. They will feel like your car is bumping a lot, and it is clearly an indication that there is something wrong. Misfires will eventually damage your engine, so you should replace this part as soon as possible.
8. Rough running at low speed
If rough running occurs only once, it is not something to worry about. But if this problem occurs frequently, you should start investigating and consider this part as a possible cause.
9. The engine suddenly stalls.
Sometimes your engine suddenly stops, and you can’t explain why. It can be annoying and incredibly dangerous if it happens on the road. You should fix this problem as soon as possible.
10. You can’t start the car.
As you turn the key or push the start button, nothing happens. Sometimes cranking the engine takes longer than you expected. In this case, a starting failure clearly indicates a failing fuel pump.
11. Overheating engine
Your car’s engine might overheat for various reasons, and a malfunctioning fuel pump is one of them. It happens because the bad pump incorrectly delivers gas to the engine, causing it to run too hot.
12. Low fuel pressure
Test your fuel pressure to determine the cause of a failing pump. You can do this with a pressure gauge found at any auto shop. Find the recommended pressure of your vehicle in its owner manual. Compare the result with the indication provided by the manufacturer.
Bad fuel pump relay symptoms
Many processes take place when you turn the key in your car. One of them is the vehicle’s ECM sending a signal to this part, commanding it to put a specific amount of gas to start your engine. It is done with the help of the fuel pump relay.
When this relay gets powered, it sends the signal to the pump. When it malfunctions, it automatically switches off. This component cannot work properly. There are 5 symptoms you should look for in a bad pump relay, and they are:
- The engine is stalling
- There is no noise from this part
- Check engine light comes on the dashboard
- You cannot start the vehicle
- Rough acceleration
