How To Tell If Your Fuel Pump Needs Replacing

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Fuel Pump Assembly 1986 Bronco II CC Image courtesy of Marion Doss on Flickr

Fuel Pump Assembly 1986 Bronco II CC Image courtesy of Marion Doss on Flickr

Your fuel pump is obviously important for your car, and it would seem as if your vehicle couldn’t move without one. That’s not always true, though. Some vehicles can limp along with a malfunctioning fuel pump for a few blocks or even miles.

But driving with a poorly performing fuel pump is not good for your vehicle, so it’s important to look out for some signs of trouble before you end up stranded or stalled out in traffic.

The fuel pump pumps fuel from your vehicle’s tank to the engine. If the fuel pump malfunctions, your engine will receive less fuel than it needs. There are some common symptoms for such a situation.

The first and most obvious symptom is that your car may not start at all, or it might start poorly. This poor start will take the form of a sputtering, stuttering, stammering sort of start, as if your car’s engine is only getting a trickle of fuel instead of the amount it needs. Your car may also stall during operation because the fuel pump is bad.

Vehicles can sputter and stall for a variety of reasons, so here’s a follow-up test. Pull your vehicle in the garage or other silent environment. When it’s not running, put the key in the ignition and turn it to the “ON” or “accessory” position. (Don’t try to start the engine.) If you have fuel injection and an electric fuel pump, the pump should start up, making a clicking or buzzing sound.

After performing the above test, if you can’t hear the fuel pump turn on, try this test. Using a fuel pressure gauge, test to make sure there’s enough fuel reaching the engine. You can take your vehicle to a technician for this test, or purchase a fuel pressure gauge at an auto parts store and do it yourself. Near the engine there should be a fuel pressure valve where you can attach the gauge. Find the recommended fuel pressure in ChiltonDIY. Compare your measurement of the fuel pressure with what it should be. If there is less pressure than there should be, that’s a sign that your fuel pump may be faltering.

Of course, there could be a few other problems causing incorrect fuel pressure, such as an obstruction in the fuel line or a bad fuel pressure regulator. If your fuel pressure is too high, suspect the fuel pressure regulator. For more information on diagnosing a fuel pump problem, check out Chilton’s online database for detailed instructions, images, and tips from our certified expert technicians to help you determine whether you need to replace your fuel pump or fuel pressure regulator, clean out the fuel lines, or something else.  Learn more about how to keep your car in tip top shape!

675 Responses to “How To Tell If Your Fuel Pump Needs Replacing”

  1. Brett says:

    I have a 1996 chevy 1 ton van with 5.7 V8. It is hard starting and wants to stall until it reaches temperature.
    I checked the gas line and the return line. Its getting plenty of fuel and the return is clear. All plug gaps wires, cap, and rotor clear. EGR also clear. I was told to rebuild throttle body. Also when running I have to hold the pedal slightly to run smooth without stalling until it reaches temp. I looked down the throttle body and it appears that it is not properly ionizing the fuel.Is it flooding itself? Please advise. ( Brett )

  2. 3d says:

    Sounds like maybe your Fuel Pump Relay (hard starts).
    My 91 chevy has ICM under Coils, this can be removed and tested at Oriellys. Check engine light ? codes?

  3. ChiltonDIY says:

    Hi Brett,

    I apologize for the late reply. I didn’t see your question.

    I would check the idle air control valve (IAC).

    The IAC controls the amount of air needed to run the vehicle, on cold starts, idle, and under engine loads, such as the air conditioner.

    Also take a look at the coolant temperature sensor. Try scanning the van for diagnostic trouble codes, this may help pin down your problem.

  4. Leo Kolodziejski says:

    I have to turn the key 5 to 6 times before my van starts when it sits over night and over the weekend it seems to take forever to start but once it start I really don’ t have any problem starting the rest of the day what could it be I have a 2000 Chevy express 2500 5.7

  5. Gerald Huckleberry says:

    Have a 95 Linc. twn car. Have put 3 new fuel pumps on it. Car is not run that often and it always start right up when pump is first put on. Will stop starting in about 2 months. Cannot hear fuel pump after that. Odds are that there is not 3 bad pumps in a row. Is there a switch that shuts pump off when ignition is off? Is there a wiring harness coupled with other wiring for the pump?

  6. ChiltonDIY says:

    Leo and Gerald, we will be back after the holiday. We invite those reading this to share your knowledge and expertise with Leo and Gerald – as well as your questions with us.
    Happy Thanksgiving everyone!

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