Car Care Tips

Tips to keep your car on the road.

Maintenance September 13, 2019

What Happens When a Fuel Pump Goes Out?

What happens when a fuel pump goes out?

Each part of your vehicle has a job. All these parts work together to make your vehicle move forward and backward safely, and depend on one another to get that job done. The fuel pump is no exception. When it’s not working properly, it can cause significant issues from front to rear bumper.

The fuel pump in your vehicle does exactly what it sounds like — it pumps fuel from the gas tank to the engine. There are some other steps in between, but we’ll get to those.

Given the crucial role of the fuel pump in making your car move forward, it’s a car part you ought to know more about. We’re walking through the warning signs of a bad fuel pump and what happens when a fuel pump goes out.

Read: What All the Symbols on Your Dashboard Mean

What Does A Fuel Pump Do?

Most modern vehicles that use an internal combustion engine are equipped with a fuel pump. Cars either have electric pumps mounted within the fuel tank, or inline pumps that work more closely toward the engine. By understanding the basic process of the fuel pump, you’ll have a better understanding of what happens when a fuel pump goes out — and how to recognize when it’s happening.

  • Fuel in your tank is drawn up through a line that heads toward the engine.  If your fuel pump is electric, it’s operated by a small motor that draws the fuel sitting in your gas tank up through a line. In older vehicles with mechanical fuel pumps, the pump moves as your camshaft spins and fuel is drawn through a line using suction.
  • Fuel travels through the fuel line and toward the carburetor or the cylinder. Depending on your engine make up, your fuel line will go directly to the cylinder or will have a pit stop elsewhere.
      1. In carbureted engines, fuel is injected with air and forms a mixture in the carburetor. Then, the mixture heads toward the cylinder.
      2. In a fuel-injected engine, fuel and air don’t mix until they reach the cylinder.
  • Air is injected into the fuel to create a mixture. Once that mixture is in the cylinder, your car is engaging a number of other parts to make your car actually run. While in the cylinder, a spark is added to the fuel.
  • Your fuel and air mixture creates another spark. Within your cylinder, the fuel and air mixture is being compressed by the piston, making it more flammable. As the piston moves and the fuel mixture becomes more compressed, the piston fires.
  • Energy released is now powering the crankshaft. You’re officially on the move. That fuel has successfully moved your car further down the road and is being expelled as exhaust after its useful life.

That five-step process has dozens of smaller steps in between, but it all starts at the fuel pump. If the fuel you’ve put into your tank can’t make its way to be mixed with air, steps two through five aren’t happening, and you’re not making progress down the road.

The process we briefly walked through is kicked off by the fuel pump, but has a number of dependencies in other parts of the vehicle in order to be successful. Timing is everything.

Read: Everything You Need to Know About Timing Belts

What Happens When A Fuel Pump Goes Out?

A faulty fuel pump will cause major performance and drive-ability issues with your vehicle. If your fuel to air ratio is off and the cylinders aren’t getting the fuel, then the pistons aren’t firing and your engine is struggling to move the vehicle forward. We’re not just talking about lower gas mileage or inefficiencies. If your fuel pump is bad enough, your car simply won’t start.

Because of the important role they play, fuel pumps are meant to be tough and withstand almost the entire life of your car. Fuel pumps have even been known to last more than 200,000 miles. Experts say that after 100,000 miles, your fuel pump is more likely to fail if you are replacing a nearby part that plays a major role in the engine.

There are a few maintenance tips that you can follow to increase the longevity of your fuel pump:

  • Always keep your gas tank at least a quarter of the way full. If you’re constantly running close to empty, this causes your gas tank to overheat, minimizing the life of the fuel pump.
  • Perform regular fuel system maintenance. Make sure your fuel system and filters are regularly inspected and replaced when necessary. By scheduling regular maintenance, you can avoid potential issues.

Read: The Car Maintenance Checklist Every Driver Needs

Warning Signs of a Faulty Fuel Pump

The warning signs of a faulty fuel pump are pretty blunt compared to some other parts of the car that can leave you guessing. If your car is experiencing these symptoms, it may be due to a fuel pump issue:

  • How does your car start? If the vehicle is struggling to start, or isn’t starting at all, your fuel pump may be damaged. If your car is requiring more than an average number of cranks to turn over, it could be a faulty fuel pump.
  • How’s your muscle power? You’ll notice a decrease in fuel efficiency, acceleration and power in your vehicle if your fuel pump is damaged. The low pressure caused by a faulty fuel pump means your engine isn’t getting the fuel and air mixture it needs to give your car that regular power.
  • Whining in the backseat. Nope, not children — your fuel tank. If your fuel tank is making a low-grade whining or whirring noise, that’s a bad sign. Your fuel pump is known to make a low, barely noticeable hum when running normally. If the pitch increases significantly, you’ll want to get it looked at by one of our experienced mechanics at Virginia Tire & Auto.

You’ll Be Going Nowhere Fast

There are a few parts of the vehicle that appear to be “the heart” of the car — the engine, the tires or the gas tank. But to get a little more specific, your fuel pump serves as the heart, pumping fuel away and into the parts of the car that need it to do their job. You can trust the heart of your car to the professionals at Virginia Tire & Auto. We know about the importance of regular maintenance and specialize in fuel system cleaning and repair.

At Virginia Tire & Auto, we want your vehicle to be running smoothly mile after mile. If you’re experiencing issues and you think it may be a fuel pump problem, it’s best to get it checked out. Stop in any of our locations to talk with one of our professional mechanics or schedule an appointment online to get your vehicle serviced.

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