Are you facing some drivability issues after changing your car’s fuel pump? Is the car stalling or hesitating to start? It is important to note that changing a fuel pump may reveal some challenges after the replacement.
Since the fuel pump is very vital in the fuel circulation of every car, it is vital to keep the component in good condition or properly fix it in case of a replacement. Otherwise, a vehicle may face several problems, especially the inability to start the engine.
However, the common problems after changing the fuel pump are not without solutions. Let’s find out the common issues and how to fix each of them.
If you just installed a new fuel pump and you are wondering what would cause a new fuel pump to go bad, this information could be helpful.
What’s a Fuel Pump?
A fuel pump is a critical component in your vehicle’s engine system. Its main job is to transport fuel from the tank to the engine, ensuring the engine receives the correct amount of fuel at the right pressure for optimal performance.
Simply put, without a functioning fuel pump, your car won’t run properly. Modern cars typically use electric fuel pumps, located inside the fuel tank.
This strategic location ensures steady fuel pressure and prevents vapor lock, a common issue in older vehicles where fuel would vaporize before reaching the engine.
Different Types of Fuel Pumps
Almost any internal combustion engine gets its fuel from a fuel pump of some kind but we’ll stay focused on automotive fuel pump here.
The main types of fuel pumps are:
- Mechanical pumps
- Electric pumps
- Direct-injection (GDI) high-pressure pumps
#1. Mechanical pumps.
Mechanical pumps were mostly found in old carburetor engines. I’ve been a mechanic for over 10 years now and I’ve never had to work on a mechanical pump on a customer’s car.
It may not be super useful knowledge for today’s technicians but knowledge is never wasted. With the arrival of direct injection, though, mechanically-driven pumps are making a comeback. Make sure your mechanical pump skills are up-to-date.
Mechanical pumps are usually installed on the side of the engine, and the piston creating the pressure is either directly in contact with the camshaft or via a connecting rod.
This type of pump was widely spread before 1985 but they weren’t simply as efficient as newer electrical models. Simply ask an old mechanic about how heat could easily vaporize the fuel in the lines, causing fuel starvation and, ultimately, engine stalls.
Anyway, you won’t see those pretty often unless you work on old muscle cars or marine engines.
#2. Electric pumps.
In today’s cars, fuel pumps are electric and are located in the fuel tank. The new design involves fewer moving parts than a mechanical pump requiring less maintenance than ever.
The in-tank system also helps in cooling the pump and the fuel preventing any risk of vaporization in the lines.
Another one of the advantages of having the pump in the fuel tank is the added safety. It may seem counter-intuitive since electricity produces sparks and sparks and fuel don’t mix well, but liquid fuel is actually non-flammable, making it a lot safer than having it near the engine where fuel leaks could easily catch on fire.
Electrical pumps are also more efficient because of the lack of resistance caused by moving mechanical components. And with the price of fuel these days, everything making your car more efficient is a no-brainer!
#3. Direct-injection (GDI) high-pressure pumps.
In the last couple of years, we also had the pleasure of seeing direct injection being installed on almost every car coming out of an assembly line. I say “pleasure” because direct injection is a lot more efficient than any other fuel system made to date.
Direct-injection pumps are usually mounted somewhere close to the engine and connected by a metal hose to a rail supplying each cylinder with its own fuel.
GDI fuel injection systems use no injectors and directly feed the engine with highly pressurized gasoline (up to 2,500 psi!), injecting it directly into the combustion chamber instead of the intake manifold.
This allows the EMS (engine management system) to continually adjust the air/fuel ratio in real-time, resulting in lower fuel consumption while producing a higher power output.
No need to say that conventional fuel-injection systems weren’t doing a really good job in adjusting the air/fuel ratio, relying on a technique we could summarize as shooting the same amount of fuel in all 4 cylinders at once, regardless of the efficiency, and monitor the O2 sensors afterward to see if it was too much or not enough.
It’s important to know that on GDI systems, the high pressure of the fuel is created by the high-pressure pump located under the hood, but the job of bringing the fuel from the tank to the high-pressure pump is still taken care of by a regular electric pump located inside the tank.
Stay aware of that when working on a GDI vehicle so as not to be mistaken about which pump is in trouble and which one you need to inspect first.
Common Problems after Changing a Fuel Pump
You may think your vehicle will run smoothly after replacing the disturbing fuel pump. But sometimes replacing it with a new one can lead to new problems.
- Difficulty starting the vehicle
- Stalling or sputtering
- The fuel gauge is not working correctly
- Decreased fuel efficiency
- Loud or unusual noises coming from the fuel pump or fuel system
- Difficulty accelerating or maintaining speed
- The gas pedal feeling “soft” or unresponsive
- Warning light for the fuel pump or fuel system illuminating on the dashboard
- Engine overheating
- Inconsistent fuel pressure
Here we will discuss the reasons for these most frequent problems one can face after replacing the fuel pump. And the most suitable solution to solve these issues.
#1. Difficulty starting the vehicle.
After replacing the fuel pump, if the car is facing difficulties in starting, there is something wrong with the fuel pump.
Reason
The incorrectly aligned fuel pump is probably the main reason behind it. But this can also happen if the fuel line is not clean and clogged.
Solution
- If the fuel line is clogged, you must clean it properly.
- If there is a alignment problem, you need to fix it properly.
#2. Stalling or sputtering.
If your car starts to stall and sputter after installing a new fuel pump, you need to find its main reason. There are a lot of factors that can cause it.
Reason
- The main reason is that the car’s engine is not getting sufficient fuel. The fuel pump was probably not fitted correctly, resulting in poor fuel pressure.
- Improper wiring can be another reason behind it. Maybe, inside there, something got short.
Solution
- The easiest way to treat this issue is to clean the fuel filter; replace it if required.
- Installing the fuel pump properly is another important thing to do.
#3. The fuel gauge is not working correctly.
If you certainly direct that the fuel gauge is not giving accurate results, then you need to recheck the fuel pump once.
Reason
- The fuel sender unit can be responsible for this problem. This unit’s main objective is to signal the gauge about the quantity of fuel left in the tank. If it is faulty, then the gauge can’t deliver accurate results.
- Another possibility is that the connection between the fuel sender unit and the gauge is broken, or there is a problem with the connector plugs.
Solution
- First, you must ensure that the oil tank sensor is working properly. If there is any fault, change the sensor.
- Then look for if any loose connection exists.
- If the problem still exists, you need to replace the gauge itself.
#4. Decreased fuel efficiency.
If you suddenly find that your car’s fuel efficiency is decreased rapidly after changing the fuel pump, then the incorrect fitting of the fuel pump can cause.
Reason
- If the pump you have installed in your car is incompatible with your vehicle, this type of problem can occur.
- Improper fitting of the fuel pump can also lead to this problem.
Solution
Please ensure that the new fuel pump is compatible with your car’s model. And it is fitted properly.
#5. Loud or unusual noises coming from the fuel pump or fuel system.
If you find a high-pitched whirring sound coming from the pump or fuel system, you need to re-check the car’s fuel pump.
Reason
If the new fuel pump is incompatible with your car’s mechanism, this type of noise can occur. A defective pump can also cause it.
Solution
An incompatible or defective fuel pump must be changed as early as possible.
#6. Difficulty accelerating or maintaining speed.
Sometimes, you can find that the car can’t give the expected acceleration after changing the fuel pump. The vehicle’s acceleration becomes slightly slower, and it can’t maintain the speed, and you need to accelerate continuously.
Reason
This type of problem can result from an inefficient or faulty fuel pump. The engine is not getting a proper supply of fuel.
Solution
By cleaning the air filters, you can get the desired results sometimes. But, most of the time, you must replace the faulty fuel pump with a new one.
#7. Warning light for the fuel pump or fuel system illuminating on the dashboard.
When there is any fuel pump issue, you can see a warning light on the dashboard to blink.
Reason
This directly indicates not having a proper and efficient fuel pump. Maybe the fuel pump is not fitted properly or incompatible with your car’s model.
Solution
Visit the mechanics again and elaborate on the problem. They can suggest what is wrong with the fuel pump. If there is an issue regarding compatibility, then it is good to purchase genuine parts from the official retailers of your car’s company.
#8. Engine overheating.
There are many reasons why a car’s engine can overheat. But after replacing the fuel pump, if you find that the car is getting overheated frequently, the fault may be the fuel pump.
Reason
The engine is not getting a proper fuel supply.
Solution
First, look for any fault in the fuel pump. If it is perfect, check the level of the radiator fluid. If it is empty, fill it immediately. Then check the coolant level. If it is empty, fill it.
#9. Inconsistent fuel pressure.
After replacing the fuel pump, if you find inconsistent fuel pressure, you need to recheck the fittings and efficiency of the new fuel pump.
Reason
A faulty fuel pump relay is the main cause of inconsistent fuel pressure. A faulty fuel pump relay can’t generate the required power for pumping. A faulty fuel pressure regulator or a clogged fuel filter can also be the reason behind it.
Solution
The most effective solution to this problem is to replace the faulty relay. Also, check the fuel filter and the fuel pressure regulator. If you find anything faulty there, change that immediately.
What should I do after a fuel pump replacement?
Follow these 10 easy steps to properly clean your gas tank and avoid damaging your new fuel pump:
- Drain the fuel tank into a safe container
- Clean out any debris or rust from the top of the fuel tank
- Remove the fuel pump
- Swirl any remaining liquid in the gas tank then pour any leftover gas and debris
- Clean the interior of the fuel tank with a low-suds soap and water mixture
- Swirl the cleaning solution inside the fuel tank
- Drain the fuel tank and dry it with compressed air
- Wipe down the fuel tank with a lint-free towel
- Visually inspect the fuel tank for any damages
- Wait approximately 30 minutes for the tank to completely dry
Tips for Preventing Common Problems after Changing Fuel Pump
Understanding these simple tips will help you avoid the common problems associated with the “post-installation” of a fuel pump in a car.
- Ensure that the fuel pump is not installed upside down but correctly installed.
- Install a new fuel filter simultaneously after changing the fuel pump. However, you may also need to find out some common problems after changing the fuel filter to avoid them.
- Instead of changing only the fuel pump, install complete fuel pump housing.
- Clean debris and rust from the fuel tank (especially the top).
- Clean the interior of the fuel tank with minimal suds detergent and water, then dry the fuel tank appropriately.
- Avoid always running on an empty fuel tank, as it can damage the fuel pump.
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.
FAQs.
Q: What else should you change when changing a fuel pump?
Whenever a car’s fuel pump is changed, it is also necessary to change the fuel filter because it is responsible for trapping dirt and other contaminants from gaining access to the fuel pump.
Dirt and other contaminants can easily result in fuel pump failure, so the best thing would be to install a new fuel filter because the old one may be bad or faulty.
Also, changing a car’s fuel pump may warrant checking the fuel line that runs from the car’s tank to its pump. In that case, it would necessarily require the installation of a new hose.
Q: How long does it take for a new fuel pump to work?
A typical fuel pump installation shouldn’t take more than 1 hour in a car. However, replacing a car’s complete fuel assembly and dropping the fuel tank will take between 2 and 3 hours.
So, a fuel pump is not expected to take the whole day before working. You may also need to find out how to start a car after replacing a fuel pump to avoid complications. However, kindly consult a professional mechanic if you ever need to change a car’s fuel pump.
Q: What happens if you put a fuel pump in the wrong?
Wrongly installing a fuel pump will make the fuel pump not supply sufficient fuel to the car’s engine.
Also, it may not work at all if installed wrongly. This can be very frustrating because you will have to adjust or remove and reinstall the fuel pump to ensure it works well.
So, it is essential to know exactly how a fuel pump should be installed to avoid the unnecessary stress of adjusting or reinstalling because of a wrong initial installation. If you can’t do it yourself, kindly consult an expert auto mechanic for the job.
Q: Why is my new fuel pump not working?
If a fuel pump does not work well or work at all, it may be due to a wrong installation. Besides wrongly installing a fuel pump, if the component fails to work, it may also be due to a fuel pump circuit problem or a bad fuel pump.
However, if you are sure that everything mentioned above is in good condition, then you may have a defective fuel pump relay, or you may have a faulty ignition switch.
In any case, kindly consult an expert auto mechanic to check what could be wrong with the fuel pump or any of its components.
Final Words
A faulty fuel pump can be a serious challenge, but it is more frustrating to install a new fuel pump and still experience some of the common problems after changing the fuel pump, as outlined above in this article.
So, it would be best to pay close attention to every detail of this article, especially in ensuring that you are able to avoid experiencing these problems from the onset.
However, if these problems surface, kindly contact a professional auto mechanic if you can’t handle them.