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!

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

  1. Joshua L says:

    Maybe you can help me! I have 1994 ford explorer xlt. Recently it started smelling like gas.. I thought I had a gas leak from maybe the tank but when I looked at the tank there was no gas coming out. But! There was gas that looked like it was falling on top of my tank and trickling down the side of the tank! So I thought I had a bad fuel line that was leaking! My car has trouble starting in the morning after sitting for about 8 hours. But it will start. Soo took it to a shop told the guy what was happening and he told me that it was the fuel sending unit. He told me it would cost me 1100 to fix! That’s crazy! He didn’t even look at the car! I’m not sure what to think. Is a fuel sending unit and a gas pump the same thing? How much do you think it would cost to fix? Do you think maybe by any chance it’s a fuel line above the tank?

    • ChiltonDIY says:

      Hi Joshua.
      I would drop the tank to see what is leaking; it could be a fuel line or the seal for the fuel pump/sending unit assembly.
      Most newer fuel pumps are usually sold as an assembly with the fuel pump and sending unit together.
      Have you actually checked the fuel pressure?
      It could be a hole in the top of the tank. If you are smelling fuel I would have the fuel system physically inspected.

  2. Jeremy says:

    Hi! I have a 72′ ford f100 with a 302, and a 2bbl carb and an inline electric pump. The fuel pump makes noise but unless the fuel tank is topped off it will stop pumping fuel to the filter/carb. I’m at a loss, is the fuel pump bad? Can it click and just not be pumping? Or is somyhing worse happening?

    • ChiltonDIY says:

      My first question is why was an electric fuel pump installed? I would check the fuel system. Is the fuel pick up screen inside the tank clogged?
      I had a 68 Mercury Cougar and the fuel tank screen was clogged with silt. I gave me a fit until I dropped the tank, cleaned out the silt and installed a new strainer screen.

      • Jeremy says:

        Not entirely sure why they added the electric fuel pump. I got the truck third hand. Too lazy to repair the mechanical pump? Not sure if the screen in clogged. That may be the next step. I am just wondering if a fuel pump can run but not hold a suction on the tank (internal seal blown and sucking air?). It won’t pull from either the external tank under the bed or the main tank behind the seat. Would I see silt in the inline fuel filter? it seemed clean. and thanks for the fast response!

        • ChiltonDIY says:

          Jeremy, I would check all the fuel lines to see if they are clear back to the tank. If the fuel lines are clear and you can blow air into the tank, than you could have a faulty pump. And yes the fuel pump can lose its prime and cause prolonged starting.

  3. Joe says:

    I have a 1995 g20 , the car starts fine but this morning I drove it I work and it was fine but during my break it died as soon as I started it , I tried again and it died after I started it ten the third time I have it had and it was fine , and also when I’m going uphill the car feels underpowered . What could be the cause of this ?

    • ChiltonDIY says:

      Hello Joe. I would scan for any related trouble codes, and check the base engine idle and timing.
      How are the filters and spark plugs?
      Check all the basics first. Import fuel pumps usually don’t have as many malfunctions as domestics.

      • Joe says:

        Sorry for the typo , I was driving at the time lol , but ill go to a shop to Check it out I don’t know anything about cars . Thanks anyways

        • ChiltonDIY says:

          You are welcome Joe. You were probably kidding about texting while driving.
          Did you know in 2011 about 1 in 4 accidents involved cellphones according to textinganddrivingsafety.com?
          11 teens die EVERY DAY from texting while driving according to the Insurance Institute for Highway Safety Fatality Facts.

  4. Zachary says:

    Hi, I have a 1989 Toyota Camry LE 6 cylinder that started cutting out until it died, I waited about 5 minutes and tried starting it and it fired right up but now when I put it in gear it feels like it isn’t getting enough gas to go. Also it is now making a weird noise whenever it is in gear any ideas?

    • ChiltonDIY says:

      Hi Zachary.
      When there is a problem starting or driving a vehicle, two of the most important checks involve the ignition and the fuel systems: Is there spark? And is there fuel? This will often lead to solving most basic problems.
      Scan the vehicle for related trouble codes.
      Is the noise coming from the motor or the transmission? Does the Camry have an automatic or a manual transmission?
      Has the fuel filter been changed in the last 20-30 thousand miles?

  5. erik says:

    Hi i have a 95 saturn sl1. Died on the freeway. Battery still fresh, when it died it was a sputtering death ” real sudden and quick” I get spark ” i put a inductive timing light on the leads” and the voltage is 14v. Im assuming a fuel issue. I will change the fuel filter reguardless, but how can i rule out the pump? It will not start after 5 minutes of run time. BUT it will start if i dont try to start it for like an hour and it will run for around 4 minutes before dying. help….

  6. Cef oli says:

    Hi I have a 1999 Buick Century costum it drives good and sounds good but once I fill it up or even put little gas in it takes two tries to start and when it’s running it has a very low idle and putting sound tell about a few minutes then it goes back to normal
    Any one that this has happened or anyone that could help would be great

    • ChiltonDIY says:

      Hi there. I would check the fuel pressure, is the check engine light on? Try scanning the vehicle for related trouble codes. What size is the engine?

      • Cef oil says:

        Yea the engine light is on and it’s the 3.1 v6 how could I check the fuel pressure?

        • ChiltonDIY says:

          First I would scan the vehicle to see what is setting the check engine light. After that if you still suspect fuel pressure you will need a fuel pressure gauge. The fuel pressure service connector is on the fuel rail.

  7. Mae says:

    Hi! I hope you can help me with this. I have a 2003 Nissan Verita. When I start my car, give it 2-5 seconds, it shuts off. Tried starting it several times but nothing happened, it shuts off. So I read somewhere that I need to change spark plugs and fuel pump. After changing, it got better and I got to go to work. But when I tried to use it after work, the engine shuts off again. I revved it up just to get me home. I’m afraid that when in idle, the engine will just shut off. I noticed also that the car’s not getting enough gas because I kept on slowing down. I don’t know what to do. Car smells of gasoline as well.

    • ChiltonDIY says:

      Caution: If the vehicle smells like gas: Don’t drive it!
      It might be running rich, that would explain the gas odor. I would inspect the fuel system and scan for trouble codes.

  8. Steve says:

    Hi! I have a ’97 Ford Explorer Sport, 2-door, 4.0, 6cylinder, overhead cam, automatic. Please help me! I don’t know what’s wrong and I don’t have a lot of money to waste!
    The FIRST symptom is that my idle would be rough but never die. Second symptom is it got harder and harder for me to get up hills. I lose power and decrease in speed so slow its embarrassing. When shifted in higher gear(2) helps a little but still lose power and speed. I feel like I have to pump my foot on the gas peddle to force gas into the engine. Then the THIRD symptom is my explorer hesitates when I start to go at a stop light as if its starving for fuel and then it catches and I speed burst ahead a little. The FOURTH symptom is that my engine makes noises like misfiring and I can smell a little fuel but not much.
    I ran an electronic test and it read out a camshaft position sensor, so I had the shop replace the camshaft position sensor and synchronizer. Still have all the same symptoms.
    With all my research, my symptoms seem to match that my fuel pump is bad. Is it my fuel pump that is the problem or some other aspect of the camshaft?
    NEW:
    Alternator
    Battery
    Camshaft Position Sensor
    Camshaft Synchronizer
    Throttle Sensor

    • Steve says:

      I forgot to add that when I hit about 60-65mph on highway, my car jolts so I let off the gas and seems ok around 50mph. Also, if when I am driving and I want to accelerate fast it does NOT happen. Its REALLY slow at accelerating! Acceleration and power keeps decreasing until I find out what to fix!
      -Thanks!

      • ChiltonDIY says:

        Hi Steve.
        There is a Technical Service Bulletin (TSB) that may apply, it is Article No. 00-20-1 and the symptoms include hesitation on acceleration and lack of fuel pressure. You can obtain the TSB, along with service, maintenance and repair information for your 1997 Ford Explorer when you subscribe at http://www.ChiltonDIY.com.
        Make sure all the basics are okay: spark plugs and wires, the air and the fuel filters. Check the compression on all cylinders. Check that the ignition system is operating properly. (Is there a good spark on all 6 cylinders?) Install a fuel pressure gauge and check the fuel pressure. It should be 35-45 psi. Check the fuel pressure regulator on the fuel rail. Unplug the vacuum line going to the regulator valve. Make sure the regulator diaphragm is not leaking fuel. It will be sucked into the vacuum line. Last but not least, check for a clogged exhaust system.
        If the catalytic converter is clogged it will cause problems on acceleration. Install a vacuum gauge and with the motor running at about 2500 rpm check the vacuum. The reading should be steady. If the vacuum reading drops off/ decreases than you have a clogged exhaust. Usually it is the catalytic converter.
        Did the original camshaft position sensor code return?

  9. Jeff says:

    Hello, great info here. Good job. I have a 98′ GMC k2500 7.4L Suburban. Truck has new lifters, push rods, cam, timing set, plugs, cap/rotor.. Lots of stuff including a fuel pressure regulator. Now truck doesn’t want to run over 3000rpm. Fuel pressure is low at 48-50psi, changed filter with no change. Will low pressure cause this back fire problem at high rpms or when a load is applied? Also no codes and had pcm reset at dealer after all engine work was done. I will try to check pressure direct from pump later this week.. thanks for any help. :)
    Oh truck starts good and runs good up to that rpm

  10. willie says:

    i have a 2000 silverado 4.3 i parked in my yard and 5 min later got back in it and it wouldnt start i changed fuel fiter and i hear pump cone on but when i pour fuel in carb it wont start and i mash pressure valve on fuel line nothing comes out i even put new coil but nothing it turns over but wont crank checked all fuses

    • ChiltonDIY says:

      Hi Willie.

      If you hear the fuel pump run, install a pressure tester to read the fuel pressure. Are you sure the gas gauge is correct? Add a few gallons of gas to be sure. The Technical Service Bulletin (TSB) below may apply:
      TSB# 04-08-49-018E: Cranks But No Start ….
      You can print, save and view TSBs and Recalls at http://www.ChiltonDIY.com when you subscribe to the information for the 2000 Silverado. There are hundreds of bulletins for the 2000 Silverado, to find this one quickly, search by the symptom “Engine won’t start” and this TSB will top the list or you can paste the TSB number in the quick search box in the upper right corner and click search.

  11. Steve says:

    I have a 2003 cadillac cts, I’ve changed the valve cover gaskets, front oil seal, throttle body Orings & gaskets, Crank position sensor, changed oil and filter, and spark plugs… and my car won’t start… It will only start if I’m smashing on the gas pedal real hard then shuts off and give a backfire… My girlfriend said she smelled gas coming from the exhaust… What can be wrong? The only code I’ve gotten was the CSP code

    • ChiltonDIY says:

      Hi Steve.
      If the vehicle ran fine before the work, back track the repair work to check for the problem. Have you tried disconnecting the battery?
      I would make sure there are no vacuum leaks and inspect the throttle body, gaskets and O-rings.
      Clear the codes and try starting the engine. Record any new codes that set.

  12. Amanda says:

    Hello I have a chevy malibu 2000 a week ago I was driving my car and it turn off on me. When I tried turning it on it would start then turn off ,I have bought a new battery and was thinking it mait be my alternator or fuel pump I don’t want to purchase any new parts if it will not fix the problem

    • ChiltonDIY says:

      Hi Amanda.
      I’m not thinking alternator, sounds like it could be a fuel pump, You need to check the actual fuel pressure with a gauge.
      If the fuel pump is within specs check the ignition system. Make sure you have good spark on all cylinders. Have you scanned the vehicle for possible diagnostic codes?
      There is a Technical Service Bulletin (TSB) that might apply:
      #00-06-04-044: Engine Hesitates, Stalls, Will Not Start …. Technical service bulletins and recalls are part of the subscription when you sign up for your vehicle at http://www.ChiltonDIY.com.

  13. Bill Burke says:

    Hello, 96nissan quest, starts runs for minute, starts losing gas feed, engine stalls , wait a couple minutes does same thing, can drive hundred yards or so, the seems to lose gas feed. Stalls again, ect.

    • ChiltonDIY says:

      Hi Bill.
      When there is a problem starting or driving a vehicle, two of the most important checks involve the ignition and the fuel systems. The questions most do-it-yourselfers attempt to answer first are:
      1. Is there spark?
      2. Is there fuel?
      Answering these two questions will often lead to solving most basic problems. For the ignition system, if there is spark, then you must determine if the fuel system is operating properly: Is there fuel?

  14. ravi says:

    Is fuel pump needs to be stop after certain time duration? if it is why we needs to stop fuel pump? help me.

    • ChiltonDIY says:

      Hi Ravi.
      Some fuel pumps cut off when the pressure reaches its limit. For instance a 96 Ford fuel pump energizes when the key is on and won’t start running again until the fuel pressure drops due to starting and driving the vehicle.
      Other fuel pumps, such as a 98 Dodge, will run continuously and the excess pressure is routed back to the fuel tank.

  15. Justin says:

    I have a 04 cavalier 2.2 l im sure its the fuel pump, cant hear it powring up. Car starts then dies right away. Cant smell gas on the carb. Relay seems to be fine. Anythi.g else i can check? Also how do i buy just a pump and not the whole assembly? Thanks

    • ChiltonDIY says:

      Hi Justin.
      If you want to be sure check the actual fuel pressure with a gauge. In your ChiltonDIY subscription for your 2004 Cavalier, follow this path for the correct fuel pressure: Fuel Systems > Fuel Controls – 2.2L (L61) > Diagnostic Information And Procedures > Fuel System > Fuel System Diagnosis.
      GM issued a Technical Service Bulletin about the fuel pump module strainer that may apply to your situation, it is TSB# 05-06-04-026A. You can read it/ save it/ print it with your 2004 Cavalier ChiltonDIY subscription.
      Justin, you must replace the fuel pump module assembly. Manufacturers do not offer just the pump for the 2004 Cavalier.

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