Figuring Out if a Fuel Pump is Going Bad

Fuel Assembly 1

If your fuel pump stops working, your car will stop moving, plain and simple. As an essential component of any vehicle with an internal combustion engine, it's important to know the signs of a failing fuel pump.

What is a Fuel Pump, and How Does It Work?

The fuel pump moves gasoline from the fuel tank to the engine, and delivers it at the correct pressure for optimal performance. Modern electric fuel pumps are activated as soon as the ignition is keyed, building pressure in the fuel system so the engine can start. While most modern vehicles are equipped with electronic fuel pumps mounted inside the fuel tank, some vehicles have either mechanical fuel pumps or inline-style fuel pumps.

Because fuel pumps are directly responsible for feeding the engine with fuel, any problems with it will cause major performance and drivability issues. When it malfunctions, a fuel pump will either deliver too much or too little fuel to your engine. When this happens, the fuel pump will produce some symptoms to alert the driver that it’s bad or failing. If these problems are left too long, the results will almost always lead to bigger issues down the road.

Signs of a Bad Fuel Pump

Fuel Assembly 2

Sputtering Engine

A tell-tale sign—and one the first signs—of a faulty fuel pump is a sputtering engine at high speeds. This usually happens when driving faster than 50 mph, and the vehicle suddenly jerks and sputters before returning to normal. Often, this issue is blamed on dirty gas, an empty fuel tank or another gas-related issue. However, a failing fuel pump that is struggling to provide a reliable stream of fuel to the engine at the correct pressure is a possibility.


Another early sign of a bad fuel pump is a hard-starting vehicle. This simply means the vehicle is more difficult to start than usual. Because fuel pumps are constantly running when the car is on, over time they will wear down and weaken. Frail fuel pumps like these will still pump gas, but it may take a little longer than usual to get the car up and going. If you’re car takes multiple cranks or turns of the key to start, the issue could very likely be the fuel pump.

Loss of Power

Bad fuel pumps with low pressure will cause an uneven fuel to air ratio in the engine, which will result in a decrease in power, acceleration, and fuel efficiency. Normal fuel pumps increase the flow of fuel as you release the brake and hit the gas. With a failing fuel pump, that flow is decreased, and the engine doesn’t have the normal power to respond to your direction. It may take a moment for pressure to be restored, at which point the engine will again run smoothly.

Sudden Acceleration/Surging

Sometimes vehicles don’t lose power when the fuel pump fails—sometimes they gain some. Failing fuel pumps often provide too much gas to the engine, causing them to accelerate without any driver aid.

This issue is often blamed on a faulty fuel filter, with the reasoning that it isn’t nabbing enough dirt and debris. However, it’s more likely due to the normal wear and tear of a fuel pump. This causes the pump to draw too little electricity needed to maintain steady speed, with sudden surges driving with higher pressure.

Car Won’t Start

This is the most serious symptom of a bad fuel pump. Drivers who ignore all the signs above will eventually experience a no-start condition.

When the fuel pump completely fails to the point of not providing enough fuel for the engine, the vehicle won’t start. The engine will still turn but won’t be able to maintain a start because of the lack of fuel.

Buying a Replacement Fuel Pump

Are you experiencing any of these issues? If so, then you should probably think about purchasing a new fuel pump sooner than later.

At Auteria, our OEM-quality fuel pumps are rigorously tested so customers receive the very best product. Plus, we sell our fuel pump assemblies directly to the consumer so you save money in the process. If you’re ready to shop, use our built-in fitment lookup tool to enter your vehicle's year, make, and mileage.