How Do I Extend the Life of My Vehicle's Fuel Pump?

Quick facts

  • Most modern vehicles use an electric fuel pump mounted inside or adjacent to the fuel tank.
  • Electric fuel pumps are cooled and lubricated by the gasoline surrounding them in the tank.
  • Running the tank below one-quarter causes the pump to work harder and run hotter.
  • The inline fuel filter should be replaced annually or every 12,000 to 15,000 miles.

The fuel pump of your vehicle is crucial for proper delivery of fuel to your vehicle's engine. An engine needs spark, fuel and compression in order to operate. There are two kinds of fuel pumps in vehicles, mechanical and electrical fuel pumps, most of today's cars are equipped with the electrical fuel pump.

The fuel pump is responsible for pressurizing fuel from a vehicle's gas tank and sending it to the engine. The mechanical fuel pumps are mounted on the engine and are usually driven by the camshaft. They use a form of vacuum in which to deliver the fuel to the engine. This type of fuel pump is found in carbureted vehicles that are becoming obsolete or are found in specialty cars.

The electronic fuel system has injectors that squirt fuel into the combustion chambers of the engine. A computer controls this system and it monitors the position of the throttle, the air-fuel ratio and the contents of the exhaust. The fuel pump is generally located on the inside or next to the fuel tank. This type of fuel system does not use vacuum to draw the fuel along the lines. The fuel pump is powered and controlled electronically. You can sometimes be able to identify the soft humming sound of the fuel pump when standing near the rear of the vehicle, when it is running or being started.

The fuel pump does not often fail in vehicles that are equipped with electronic fuel injection. But when it does fail, it can begin as an intermittent problem, or the engine will sputter and die, or it will just crank and not actually start up and run.

The best way to maintain your fuel system and get longevity out of your fuel pump is pretty simple:

These simple steps can help to avoid restrictions, helps maintain proper air fuel ratio mixture and reduces undue strain on the fuel pump. Following these steps can also improve throttle response, smoother idle, improved fuel economy and lessen harmful emissions.

Steve and Karen Johnston are owners of All About Automotive in Historic Downtown Gresham. Happy Motoring!

Frequently asked questions

Common questions

What are the early signs that a fuel pump is starting to fail?

A failing fuel pump often gives intermittent symptoms before complete failure. These include the engine hesitating or sputtering under acceleration, stalling at highway speeds, or difficulty restarting when the engine is hot. A whining noise from the fuel tank area that worsens under load is another common indicator. Because these symptoms overlap with other fuel system issues, a fuel pressure test is the definitive way to confirm whether the pump output has dropped below specification.

Why does running the fuel tank low damage the fuel pump?

Electric fuel pumps rely on the surrounding gasoline for both cooling and lubrication. When the tank is consistently run low, the pump has less fuel available to cool it during operation, causing it to run hotter. Heat is the primary enemy of fuel pump longevity. Additionally, sediment that settles at the bottom of the tank can be drawn through the pump strainer when fuel levels are low, accelerating wear on internal pump components.

How does a clogged fuel filter affect the fuel pump?

A restricted fuel filter forces the pump to work against increased resistance to maintain the pressure the injectors need. This elevated workload generates more heat and draws more electrical current, both of which shorten the pump's service life. In some cases, a failing pump is actually a pump that has been strained by a long-overdue filter replacement. Changing the filter on schedule is the most cost-effective way to protect the pump. A filter costs a fraction of what a pump replacement does.

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