Bad Fuel Pump: Symptoms, Causes & Fixes

Bad Fuel Pump

Fuel pumps are like the central system of modern-day automobiles. Without the fuel pump, delivering fuel to the combustion chamber will be an impossible task. This is why fuel pumps, like the fuel injectors, are a very vital aspect of our vehicles. 

If you have a bad fuel pump some common symptoms are The Gas Tank Makes a Moaning Sound, increased fuel consumption, The Engine makes a Stuttering Sound and a Hard Engine start. Every experienced driver should be able to tell when their fuel pumps are in good or bad condition. Having this knowledge will help them find a credible solution for it. When fuel pumps go bad, they develop signs that should serve as an indication that they need to be fixed or replaced. 

In this article, we will be looking at the various symptoms and causes of Bad fuel pumps. But first, let’s get a better understanding of what fuel pumps are.

What is a Fuel Pump?

We can simply say a fuel pump is a device that pumps fuel through a hose to the combustion chamber of a vehicle engine. The way a water pump works is similar to that of a fuel pump. It is the job of the fuel pump to move fuel from one aspect to another. When you put fuel into your vehicle tank, it is the fuel pump that helps to transfer fuel from the tank to your vehicle’s engine. 

The working process of a fuel pump is simple. If your vehicle comes with an electric fuel pump, a small motor helps to draw gas from the tank through a line to the engine. For a machine-operated fuel pump, fuel gets into the engine through the suction process, as the camshaft spins. 

Whether electric or mechanical, fuel from the tank passes through the fuel line to the cylinder or carb, depending on your engine makeup. For a carb-based engine, the fuel will stop to mix with air before going to the cylinder. However, for fuel-injected, fuel mixes with air when it gets to the cylinder. 

The piston causes compression in the cylinder to cause a spark (as the piston fires) to make the fuel more flammable. The energy created in the cylinder sends power to the engine after powering the crankshaft. 

Symptoms of Bad Fuel Pump

We use various types of fuel pumps in our vehicles, and there will always come a time when our fuel pumps are bound to develop one issue or the other. However, a bad fuel pump will display some signs that will give you a clue that they are bad. Let’s take a look at some of them. 

  • The Gas Tank Makes a Moaning Sound

Once your fuel tank begins to make a moaning sound, it is a sign that your fuel pump is faulty. Interestingly so many of us might mistake the moaning sound coming from the fuel tank to be from the engine. Once you start up your vehicle’s engine, a click sound will be produced by a fully functioning fuel pump. When driving, it makes a low humming sound. 

  • Increased fuel consumption

Another sign you’ll notice when your fuel pump is getting bad is an increase in the amount of fuel your car consumes. You will notice the decreased fuel efficiency due to low pressure resulting from a damaged fuel pump. When you observe this, it means the vehicle engine is not getting enough air-to-fuel ratio. The car will not receive the needed power from the engine and will consume much more fuel than normal. 

  • The Engine makes a Stuttering Sound

Engine stuttering is the most common symptom of a bad fuel pump. When you’re driving, the fuel pump delivers fuel to the engine. However, when you’re driving at a top speed, the fuel pump might probably not transfer the correct amount of fuel to the engine, and this can cause your engine to stutter. You can test this out by driving your car at top speed to see if the engine will stutter. If the engine stutters, then you can be sure that it’s a bad fuel pump.

  • Hard Engine Start

As time goes on, there’s a possibility that your fuel pump will wear out. Once weakened, the fuel pump can find it challenging to supply fuel freely to the engine. At this stage, the engine will be difficult to start. 

Causes of Bad Fuel Pump

Different things can cause a fuel pump to fail; however, there are three common causes.

  •  Electrical Fault

It is one of the primary reasons for bad fuel pumps. Some of these electrical faults are loose connectors, melted connectors, melted wires, and rusted connectors. 

  • Contaminated Fuel

Contaminated fuel is caused by moisture and debris from corrosion, leading to a bad fuel pump.

  • Blocked Filters

Once the contaminants in the fuel tank increase, they block the filter and strainers, which eventually leads to a non-functioning fuel pump.

How to Fix Bad Fuel Pump?

  • Apply External Pressure

Since a failing fuel pump can’t send fuel to the engine without enough pressure, apply external pressure to get your car running again.

  • Use a Pressure Gauge

This option is very common. Connect the pressure gauge to the fuel pump’s port, and the gauge will get your vehicle working. 

  • Maintain the Engines Temperature

Once the engine is heating up, it will make it impossible for the fuel pumps to function; it is why you must maintain the engine’s temperature to get the fuel pump functional. 

Way to Avoid Fuel Pump Failure

Besides the fixing and replacement methods, you can also do some things to ensure maintenance. If you try to prevent damage to the fuel pump, you will be saving yourself the stress and a lot of money.  

Here are a few maintenance procedures you can use to expand the lifespan and longevity of your car fuel pump:

Make sure you take the fuel pump for a scheduled servicing and maintenance. Take your car’s fuel filter for regular inspection. This will inform you whether they’re failing or need replacement and fixing. 

Another way to avoid potential fuel pump issues is to ensure that you always fill your gas tank about a quarter full. Don’t drive your car if the fuel tank is half or almost empty. This way, you’ll minimize the cost of a fuel pump.

Final Thoughts

Now you are aware of the symptoms and causes of a bad fuel pump. If you have a severely bad fuel pump, you can visit your mechanic to help you get a lasting solution. The fuel pumps of our vehicle are vital, and you’ll need to monitor them.