7 Common Problems After Changing Fuel Pump (How To Avoid Them)

I am often asked what to expect after recently changing out a fuel pump on a vehicle. Because the fuel pump is such a major component of any vehicle, it is important to know the potential issues that could arise after installation.

The most common problems you can experience after changing your fuel pump are engine issues, fuel gauge problems, and problems starting your vehicle. Engine issues like not starting properly or random revving are common and can cause unsafe driving conditions if not addressed. Fuel gauge problems like inaccurate readings are also commonly reported.

This guide will help you navigate the different issues surrounding recent fuel pump replacements and how you can avoid them.

Common Issues After Changing Your Fuel Pump

Fuel Gauge Reading Problems

Fuel gauge reading problems are common after changing your fuel pump and are commonly caused by a faulty sending unit. The sending unit is responsible for letting the fuel gauge know accurately how much fuel is in the tank. If it is not working properly, it can cause a false fuel reading.

Excess buildup of dirt and debris can cause your sending unit to fail. This is most common if you do not regularly clean your fuel tank or allow items inside that shouldn’t be there. In some cases, the sending unit may have simply reached the end of its life and will need to be replaced.

To resolve issues with the fuel gauge reading incorrectly, it is best to have your car serviced by a licensed mechanic. They will be able to determine the exact cause of your problem and offer the most insight into potential solutions.

Engine Start Problems

Engine start problems are also common after changing a fuel pump and are most commonly caused by a faulty fuel pump or fuel line clog. This will be especially noticeable after recently adding gas to the tank of your car.

A fuel pump that was not installed with the correct alignment will often cause issues with the engine. If your fuel line is clogged, it will need to be cleared before fuel will be properly passed to the engine of your car.

To resolve issues with a misaligned fuel pump, you will need to reinstall it correctly before your engine will work properly. Cleaning out the fuel line will help remove any clogs present keeping fuel from reaching your engine.

Fuel Gauge Not Working

The fuel gauge may not work at all after you have recently changed your fuel pump due to issues with the sender unit. The sender unit is responsible for communicating the amount of gas in the tank to the fuel gauge.

Wiring issues, improper fuel gauge installation, and connector plug issues are common causes of sender unit malfunctions. To resolve these issues, you will need to check your oil tank sensor and ensure that it is connected correctly. If it is not, you will need to adjust it so that it gives a more accurate reading.

You should also check any wiring involved with your fuel gauge to test for any loose connections. In some extreme cases, you may find that you need to replace the whole fuel gauge if it is no longer working properly.

Engine Stalling

Engine stalling is another common issue to experience after recently changing your fuel pump and is primarily caused by an improperly installed or blocked fuel filter. The fuel filter is responsible for keeping debris and buildup out of the engine.

Over time, the fuel filter can become worn or blocked in a way that can cause your engine to not receive fuel properly. This can cause your engine to stall as it struggles to get the proper amounts of fuel. Because of this, it is recommended that you change the fuel filter any time you change the fuel pump in your vehicle.

If you are having these issues after recently getting your fuel pump changed, inspect the fuel pump installation and adjust it if necessary. If you notice a significant buildup on your fuel filter, replace it with a new one to resolve your issue.

Sudden Engine Revs Issues

Sudden engine revving, or acceleration, is another common issue that can be experienced after recently changing your fuel pump. Sudden engine revving is typically caused by issues with the accelerator pedal, the computer system, or the engine block itself.

Sudden engine revving can be a serious issue and should be addressed as soon as possible. You should take your car to a licensed mechanic to be serviced. A licensed mechanic will be able to diagnose your issue and offer more insight into possible solutions.

Whirring Noises

High-pitched whirring noises are also common after recently changing the fuel pump. This is most common when the fuel pump you have installed is not compatible with your vehicle’s fuel system or if it was faulty upon installation.

In addition to whirring noises, a fuel pump that is not compatible can cause a loss in fuel efficiency and more general engine noise. To resolve this, you should replace the incompatible fuel pump with one that matches your vehicle’s fuel system.

Now that you understand the common issues you can encounter, you can begin to explore more in-depth what a fuel pump does and how it works.

What Is A Fuel Pump And What Does It Do?

A fuel pump transports the fuel from your gas tank to your engine. This makes it one of the most vital components of your vehicle and one that should be maintained properly. The fuel pump is generally located inside the fuel tank and uses a variety of means to siphon and transport the gas to the engine.

The most common type of fuel pump is the electric fuel pump, which is always located inside the fuel tank. Electric fuel pumps use a small electric motor to draw gasoline out of the tank and up the fuel lines into the engine.

Electric fuel pumps are much more reliable and efficient that their mechanical counterparts. They are also much less prone to leaking than mechanical fuel pumps. Which type of fuel pump you choose can help you estimate the overall cost of your replacement.

Average Cost To Replace A Fuel Pump

The average cost to replace a fuel pump can be anywhere between $250 to $1000. The actual price will depend on several different factors including the make and model of your car and the labor involved. Typically, the parts associated with fuel pump replacement total around $100 to $800. Labor costs can be expected to total anywhere between  $125 to $250.

It is important to understand how long it will take your new fuel pump to work once you have purchased and installed it.

How Long Does It Take For A New Fuel Pump To Work?

A new fuel pump will begin to work as soon as it has been installed properly. Once you have installed your new fuel pump, it will automatically begin to transport gas from your tank to your engine. If your new fuel pump is not working right after installation is complete, you may have made a mistake somewhere in the installation process.

The installation process for a new fuel pump can take between one to three hours, depending on the complexity of your vehicle’s fuel system. Once this process is complete, it should be working as soon as you crank the engine of your car.

If your new fuel pump is not working properly, there are some things you can do to test it for issues. These testing methods will be detailed in the next section.

How To Test Fuel Pump For Problems

To test the fuel pump for issues, the first thing you should do is fill your car up with gas. This will ensure that the fuel pump has access to a full reservoir of gas during the testing process. Next, you should locate your fuel pump relay and test it for continuity with a multimeter.

If you do not get the proper electrical reading out of the relay, you will need to replace it with one that works properly. Finally, you should check all electrical connections associated with the fuel pump. If you notice any connectors that are loose or damaged, you will need to repair or replace them.

In addition to testing for fuel pump issues, there are some other components of your vehicle that should be inspected and replaced if necessary.

Are There Other Parts I Can Change Together With My Fuel Pump?

You should change your fuel pump filter any time that you are planning to replace your fuel pump. The fuel pump filter is responsible for keeping debris from the gas tank of your car from entering the engine block.

Replacing both the fuel pump and the fuel filter at the same time can cut down on the chances of fuel blockages in the future. Your fuel filter will likely need replacing far more often than the fuel pump itself, as it is a heavily utilized component.  Because of this, it is advised that you go ahead and change the fuel filter with the fuel pump to avoid any problems.

So you may be wondering what you should do after you replace your fuel pump. This will be covered in the next section.

What Should I Do After A Fuel Pump Replacement?

The first thing you should do after a fuel pump replacement is to check your fuel filter for clogs. This is especially important if you did not replace the fuel filter with the fuel pump. A clogged fuel filter will cause your new fuel pump to not work properly.

Next, you should inspect your fuel lines for any visible leaks. Any leaks you find will need to be repaired as soon as possible. Finally, double-check that you have installed the right fuel pump for your particular vehicle. Using an incompatible fuel pump can cause more serious issues for you down the line.

It is important to understand how to prevent the common issues associated with changing a fuel pump. These preventative methods will be discussed in the next section.

How To Prevent Common Problems After Changing Fuel Pump?

To prevent common problems after changing your fuel pump, you should first ensure that the fuel pump is compatible with your vehicle’s fuel system. This will help ensure that there are no compatibility issues in the future that could cause more serious issues.

Next, you should ensure that the fuel pump is installed correctly, including checking the relay and wiring harness. To avoid many of the issues associated with changing a fuel pump, you should change the entire fuel pump housing instead of just the fuel pump. This will lower your chances of having issues with your installation.

Finally, you should keep your vehicle’s fuel tank filled over 25% to ensure that the fuel tank has enough fuel to properly disperse through the fuel pump. Performing the appropriate tests can help determine whether or not you will have issues with your newly installed fuel pump in the future.

Now that you know a little more about fuel pumps in general, some frequently asked questions have been detailed in the next section.

Listed below are some of the common questions I have heard regarding fuel pumps and the different problems you can have when replacing one.

What Else Should You Change When Changing A Fuel Pump?

The fuel filter should always be changed any time you are planning a fuel pump replacement. This will allow your fuel pump to operate with a clean filter and remove the potential of any blockages that could be present in the old filter.

Another component that you should consider changing is the fuel lines. You will only need to change your fuel lines if you notice they have visible leaks or damage.

What Happens If You Install A Fuel Pump Wrong?

Installing a fuel pump wrong can cause issues with fuel efficiency and general engine trouble. Because the fuel pump is the main component that transports fuel from the tank to the engine, an improperly installed fuel pump could cause your engine to not start.

Because of this, it is extremely important that you correctly install your new fuel pump and test for any issues ahead of time. This will help you avoid more serious problems in the future.

Why Is My New Fuel Pump Not Working?

The most common causes of a new fuel pump not working properly are improper installation, faulty wiring or relay, or a defective fuel pump. You should first check and make sure that the fuel pump you purchased is not damaged in some.

After that, check the wiring and relay components, and the installation quality of your fuel pump. If you can still not find the cause of your issue, you may need to replace the fuel pump with a new one or consult a professional for more information.

Can I Drive On A Bad Fuel Pump?

It is highly advised that you do not drive on a bad fuel pump. Because a bad fuel pump can cause issues like random engine revving and engine stalling, it can potentially cause unsafe driving conditions for you and other drivers.

You should address any fuel pump issues that you may be having as soon as possible to avoid more serious issues in the future. In some cases, you will not be able to crank the engine properly to begin with if the fuel pump issues are serious enough.

Can A New Fuel Pump Be Defective?

A new fuel pump can be defective, though this is a rare occurrence. As most fuel pumps you purchase will have undergone some level of quality control, the likelihood of purchasing a defective one is extremely low.

That being said, no manufacturing process is perfect, so defective units could exist. If you suspect that you have purchased a defective fuel pump, you should inspect it and return it as soon as possible for one that is working properly.


Addressing issues with your fuel pump after recently changing it out is important for maintaining the functionality and safety of your vehicle. Because of this, it is important that you recognize the signs of potential issues commonly experienced after recently changing a fuel pump.

If you notice engine issues, fuel gauge problems, or whirring noises, these are all strong indicators that there is an issue with the fuel pump or some other associated component. You should address any issues that you are aware of as soon as possible to avoid more serious issues in the future.