Signs a Fuel Pump Is Failing

by Steve SmithUpdated August 16, 2023

What is a Fuel Pump?

The fuel pump is an important part of a vehicle's fuel system. Its main function is to supply fuel from the fuel tank to the engine at the pressure required for performance. Here are the main components of the fuel pump:

  1. Electric Motor:‌ Most modern vehicles use electric fuel pumps. The electric motor is the main driving element of the pump.
  2. Impeller:‌ The impeller, also called impeller, is driven by an electric motor. Rotate to build pressure and push fuel from the pump to the engine.
  3. Fuel Filter:‌ Acts as a filter to prevent debris from the fuel tank from entering and damaging the fuel pump.
  4. Check Valve:‌ The check valve maintains fuel pressure in the fuel line when the engine is off. This ensures instant fuel delivery upon vehicle restart.
  5. Pressure Regulator:‌ In some systems, a pressure regulator is used to maintain the correct pressure in the fuel line.Normally it returns excess fuel to the tank.
  6. Fuel Pump Relay:‌ This electrical switch turns the fuel pump on and off. When you turn the ignition key, the relay sends an electrical signal to start the fuel pump. If the engine is running, the relay will continue to operate the pump until the engine is stopped.
  7. Fuel Lines/Lines:‌ These are the lines that carry fuel from the pump to the engine.
  8. Fuel Filter:‌ While not a part of the pump itself, the fuel filter is an important part of the fuel system. It is usually found along the fuel line (between the fuel tank and the engine) and filters dirt and rust particles from the fuel.
  9. Fuel tank:‌ again not part of the pump, but a main part of the fuel system. This is where the fuel is stored before it is sent to the engine.

The fuel pump is essential for the functioning of the engine. If it is not running properly, the engine may not run or run poorly due to insufficient fuel supply.

Fuel Pump Replacement Cost

Typically, the total cost to replace a fuel pump is between ‌$900‌ to ‌$1,200‌ including parts and labor. Mechanics charge an hourly rate between ‌$100‌ to ‌$200‌ depending on experience and the complexity of the job.

How long will fuel pump replacement take?

Fuel pump replacement can take anywhere from ‌4‌ to ‌5 hours‌.

The replacement time varies due to:

  • Vehicle Design
  • Whether associated components are being replaced at the same time (e.g. water pump)


  • These are estimated costs and actual costs may vary.
  • Always seek out a trusted professional for a specific quote based on your specific vehicle and situation.
  • The cost of replacing a timing belt can vary widely depending on:
    • The vehicle make and model
    • The specific complexity of the task
    • Where you live.

How Long Does a Fuel Pump Last?

The life of a fuel pump can vary widely and depends on many factors including the make and model of the vehicle, the quality of the fuel used, and how often the vehicle is used. On average, however, a fuel pump should last ‌100,000 to 150,000 miles‌.

Proper maintenance can extend the life of the fuel pump. For example, constantly driving a fuel-efficient car can cause the fuel pump to work harder and wear out faster, since the fuel in many vehicles cools and lubricates the pump. Therefore, keeping the tank at least a quarter full can help prolong pump life.

It is also important to use good quality fuel as poor quality fuel can cause deposits or damage to the fuel system, including the fuel pump. Replacing the fuel filter regularly, as recommended by the vehicle manufacturer, can also help extend the life of your fuel pump by preventing dirt from entering the pump and causing damage.

As with any auto part, fuel pumps can fail prematurely. Therefore, it is important to know the symptoms of a fuel pump failure and to consult a professional if your vehicle exhibits any of these symptoms.

Urgency of Fuel Pump Replacement

The urgent need to replace a defective fuel pump is relatively high. That's why it's important to fix the problem quickly:

  • Vehicle inoperative:‌ A fuel pump failure may cause the engine to stall or prevent the vehicle from starting. This can immobilize you and prevent you from driving until the pump is replaced.
  • Safety considerations:‌ Sudden power failure while driving due to fuel pump failure can be dangerous, especially in certain situations like entering a highway or driving in heavy traffic. This can affect the ability to control the vehicle and respond effectively to road conditions.
  • Risk of engine damage:‌ A defective fuel pump can lead to a lean air/fuel mixture and thus to overheating of the engine. This can potentially lead to engine damage and even engine failure if not addressed quickly.
  • Other fuel system damage:‌ Failure of the fuel pump can put additional stress on other fuel system components such as the fuel filter or fuel injectors. Continuing to operate the vehicle with a damaged pump can damage these parts, leading to more extensive repairs.
  • Inefficient fuel delivery:‌ A weak or malfunctioning fuel pump may not be delivering fuel at the correct pressure or volume that the engine requires.This can lead to poor engine performance, decreased fuel efficiency, and increased emissions.

Given these reasons, if you suspect a problem with your fuel pump based on the symptoms or diagnostics, it's crucial to have it replaced as soon as possible. Addressing the issue promptly can help avoid further damage, potential safety risks, and inconvenience associated with a non-operational vehicle.

What are the Symptoms of a Bad Fuel Pump?

Loss of Power

The most common symptom of a fuel pump failure is a loss of power while driving. This occurs because there is less pressure in the fuel lines, and the engine is actually receiving less gas or intermittent streams of gas. This may happen while driving on the highway at high speeds, climbing up a hill or when you press the gas to drive away from a standing stop. A loss of power may also be attributed to faulty oxygen sensors or engine problems, but often it is the fuel pump, especially in older cars.

Engine Misfire at Startup

Another sign of a bad fuel pump is a misfiring engine which results in lurching car movements. This most often occurs when driving on the highway or at higher speeds above 50 miles per hour. The engine is actually lacking fuel so it is dying and then starting back up again. The drop in fuel pressure is the cause. Sometimes moisture and condensation will get into the tank, and cause a similar problem. Don't be fooled, however. More often than not, this is a sign the fuel pump is dying.

No Start

A no-start condition may be one of the most commonly confused symptoms of a failing fuel pump as many mechanics will tell you this could be due to the solenoid or spark plugs. However, it is often a sign the fuel pump is going bad. If your battery is charged and the car starter is firing (you hear the engine straining to start), but the engine does not turn over and start, it is probably due to a lack of fuel from the pump. To be certain, check your spark plugs and replace them if necessary. Then have the fuel pump inspected and replaced.

Empty Gas Tank

Pay special attention to the fuel pump if your car has stalled due to an empty gas tank. When the gas tank runs empty, it strains the pump and can cause it to fail. Always keep the car filled up and never try to drive on an empty tank.

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