What Is a Fuel Pump and Why Is it Important?

If you could look inside your fuel tank, you would find a cylindrical pump. It’s the fuel pump, and its job is to pump fuel into the engine and to maintain a certain fuel system pressure. It may be smaller than many parts in your car, but it actually plays a huge role in the operation of your engine.

How a Fuel Pump Works

Ford fuel pump

The fuel pump draws gas out of your tank and then pumps it to the engine through a flexible fuel line. When the gas reaches the engine, it is either directly injected into the combustion chamber, or injected into the intake manifold.

Modern electric fuel pumps typically use a turbine spinning at high speed to suck fuel from the bottom of the tank. The fuel then flows through the pump and into the fuel line. The pump uses a system of pressure relief valves to manage the fuel pressure very precisely.

It may seem odd that the fuel pump is located inside the fuel tank, where it is submerged in fuel. This is possible because gasoline is a very poor conductor of electricity. Gasoline actually flows over the electric motor inside the fuel pump and keeps it cool. Gasoline also acts as a lubricant for the moving parts of the pump.

Causes of Fuel Pump Failure

The most common causes of fuel pump failure are:

  • Premature Wear Due to Overheating - Electric motors last longer when kept cool. When a fuel tank is low, the fuel pump is not submerged, so it has less cooling. It also has to work harder to generate pressure, which makes the pump run hotter. The best way to prevent this problem is to always fill the tank to full, and to never run lower than 1/4 tank.
  • Failure Due To Running Out of Gas - Running out of gas completely just once can cause the fuel pump to fail. Without any gas, the pump has no lubricant and no cooling. If you do run out of gas, switch off the ignition immediately. Most fuel pumps are running when the ignition is switched on, even if the engine is not running.
  • Failure Due to Pump Corrosion - Corrosion of the pump can occur if the car sits for a while with a partially full tank of gas. Ethanol attracts water from the air, and the water corrodes the pump. (Most gas has some ethanol in it.) To prevent this problem when storing a car, you can either:
    • Drain the tank.
    • Treat the fuel with an additive that helps to prevent water accumulation.

Why a Broken Fuel Pump Needs to be Replaced Right Away

Change pump

Image Credit: WSORR

When your fuel pump begins to fail, a number of symptoms may arise:

  • Difficulty starting the engine
  • Lack of power
  • Weak acceleration
  • Whine from the fuel tank

If a failing fuel pump isn’t replaced, it’ll eventually stop working and prevent the engine from starting at all. It’s not a situation you’d want to get into, especially if you’re away from home.

Why Use an OEM Replacement Fuel Pump?

If the fuel pump in your Ford fails, you want to replace it with the exact same model made by the same company that makes your car’s original parts. These parts are called OEM (original equipment manufacturer) parts. They’re a much safer bet than aftermarket parts. OEM fuel pumps are engineered specifically to work optimally with your fuel system. Many aftermarket fuel pumps have a universal design, meaning they may not provide the exact fuel pressure required by your vehicle.

Here are some quick links to our top selling OEM Ford fuel pumps:

  • Part No. 8L3Z-9H307-B: For 2004-2008 F-150 and Lincoln Mark LT models
  • Part No. F6TZ-9A407-CC: For 1992-1997 Bronco, F-150, F-250, and F-350 models
  • Part No. F85Z-9H307-AB: For 1997-1998 F-150 and F-250 models
  • Part No. XL3Z-9H307-DB: For 1999-2004 F-150 and F-250 models
  • Part No. YW4Z-9275-BC: For 2000-2005 Thunderbird and Lincoln LS models

If you don’t see your Ford vehicle on the list, don’t worry. You can easily do a search on your car here to find the right part number.