How to Tell if Your Fuel Pump is Bad

Some signs of a bad fuel pump are painfully obvious, while others might lead you to believe something else is the root cause of your problems. These are some signs your fuel pump may need to be replaced.

Your Car Won’t Start

A car that won’t start is often caused by a faulty fuel pump. Your fuel pump pushes fuel into your engine, which combusts fuel to power the vehicle. If it’s not getting fuel—because the fuel pump won’t deliver it—it can’t turn over.

If this is happening to you, chances are it’s the fuel pump—especially if you feel everything else is operating correctly. One tell-tale sign that your fuel pump is the cause for your vehicle not being able to start is that you may hear a popping sound, like your engine is not getting enough fuel, which hints that the fuel pump is just fading fast.

Your Vehicle has a Whining Noise

Car whining noises are often attributed to the belt system, but that’s not always why your car whines. Be mindful of where you hear the whine coming from!

If you hear a whine emanating from the fuel tank, it’s typically a precursor for a loss of pressure, which means a total failure of your fuel pump is on the horizon. This whining noise may last months, too. If you hear a whining noise, get your fuel pump checked out.

Your Car is Stalling

A car stalling is frustrating, embarrassing, and can be dangerous. 

When a car stalls due to a bad fuel pump, it’s often because the pump is just not delivering enough fuel at idle, which is a great sign that it’s near the end of its life. If it can’t deliver an essential volume of fuel to keep your engine purring, it’s faulty.

Your Vehicle’s Performance is Lacking

Do you feel like your car isn’t as responsive or quick as it used to be? The problem could be the fuel pump.

Your vehicle is an orchestra of mechanics, and the fuel pump plays a vital role. When you want your car to perform, the fuel pump delivers fuel quickly to the engine to do what you want. Your car feels lethargic if the fuel pump can’t spring into action.

Your Vehicle’s Performance is Better than Expected

Conversely, your fuel pump might not be regulating fuel delivery properly, which can lead to delivering too much fuel to the engine. Your engine is designed to burn through the fuel it’s given, so if it’s getting too much, it’ll try to use it, leading to surging performance and your car “jumping” forward when you least expect it.

You’re Experiencing Loss of Power, Especially when the Vehicle is Stressed

If you’re going up a hill or trying to overtake someone on the road - but your car won’t speed up appropriately, or at all - this could be because the fuel pump is faulty.

Decreased Fuel Efficiency

Your car’s fuel efficiency is directly tied to the fuel pump’s performance. If the pump delivers too much fuel, your miles per gallon will plummet, which will cost you money via more stops at the gas station. 

How to Test Fuel Pump Performance

You can test your fuel pump with a fuel pressure gauge. We also suggest having a friend available, as diagnosing your fuel pump issues will require someone to read the gauge while another person steps on the accelerator.

Here’s How to Test Your Fuel Pump

• Start your car and let it idle for 10-15 minutes

• Install the fuel pressure gauge

• Activate the fuel pump by lightly pressing on the accelerator

• Observe the pressure reading on the gauge

• Compare the readings to your vehicle's recommended pressure specifications. If anything is amiss, your car may need further testing or a trip to the mechanic.

Troubleshooting and Advice

Can a Fuel Pump be Repaired, or Must I Always Replace It?

A fuel pump can’t truly be repaired. If you’re experiencing issues that are found to be caused by the fuel pump, replacement is necessary. Keeping your car’s fuel filter clean is the best way to avoid a costly fuel pump replacement.

How Much Does it Cost to Replace a Fuel Pump?

This depends on the vehicle, but fuel pumps typically cost between $400 and $1,000.

How Long do Fuel Pumps Last?

This is hard to know and depends on the type of fuel pump you have. Older vehicles have mechanical fuel pumps that fail faster, while newer cars have electrical fuel pumps that are more reliable. In newer cars, it’s common to go over 100,000 miles without a fuel pump replacement.

What Else Could be Causing my Issues?

Depending on the issue you’re having, your issue may be caused by one or more of the following issues:

• An empty or nearly empty fuel tank

• Ignition switch issues

• Clogged fuel filter

• Clogged or faulty fuel line

• Faulty fuel injectors

• Malfunctioning fuel pressure regulator

• Misfiring spark plugs