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!

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

  1. eli says:

    I have a 96 mustang it starts up good but when I put in reverse it stops wondering if you know whats wrong with it

    • ChiltonDIY says:

      Hi Eli.
      Did you scan for trouble codes? I would.
      It sounds like an idle control malfunction. The idle air control (IAC) valve controls the engine idle speed and dashpot functions. The valve is located on the side of the throttle body. This valve allows the necessary amount of air, as determined by the powertrain control module (PCM) and controlled by a duty cycle signal, to bypass the throttle plate in order to maintain the proper idle speed. Testing as well as operation and removal and installation are covered in your 1996 Mustang ChiltonDIY subscription.
      Inspect the throttle plate and clean it if needed.

  2. Chris says:

    Hello! I have a 99 Miata and it won’t start. It will try to start with a little starter fluid sprayed into the throttle body which leads me to believe it’s a fuel problem. My fuel filter could use replacing, but is not clogged. When I remove the fuel line from the filter and turn the key to the on position, there is no difference in the amount of gas coming from the fuel line. Does this mean my fuel pump isn’t working? I hear a quiet hum coming from the girl pump assembly mount inside the car, but not from the fill hole. Could I hear this even though the pump isn’t working? Could I just be hearing the relay or the electric current and not the pump motor? Could the motor be running but not pumping gas? Please help! Thanks in advance!

    • ChiltonDIY says:

      Hi Chris,
      You could be hearing the pump run; verify you do have fuel in the tank. Unplug the fuel pump connector. If the noise stops you know it is the pump running. The strainer inside the tank could be clogged, or the pump hose could be leaking pressure.

  3. peter says:

    Hi chilton my 2003 dodge ram didnt start earlier today it would stall for a while after numerous times of trying to start the engine it would kil my battery what do you think it could be?

  4. Kris Wright says:

    I NEED HELP!
    My husband passed away and I am wanting to sell his truck it is a 1996 Ford F150 XLT 5.0.
    The truck always ran fine until a friend of his took the truck to clean it up for me to sell, he put some new hoses on and put gas in the wrong tank (it has two tanks, one worked one did not) and it has never started since. We put gas in the correct tank, replaced the Ignition coil and the ignition control module and still can’t get a spark. When replaced the ICM it sparked once and then never sparked again. After putting the gas in the correct tank we could smell fuel in the carb which I think was a good thing. The truck just won’t spark. Any suggestions? I am running out of money to buy parts to get it running. I just don’t understand, it ran great when the friend took it. :-(
    Thank you for anything you can do to help me!!

  5. Kris Wright says:

    Oh I might add when we replaced the coil it did not make the truck spark, it only sparked once when we replaced the ICM. Also, when a friend put the tester on it blinked for the ICM that is why we replaced it but as I said, it sparked once with the new one and never sparked again. We have checked all fuses as well.

    • ChiltonDIY says:

      Hi Kris. If you are not seeing spark check the EEC-V power relay. This is located under the hood in the power distribution box. When your friend cleaned up the truck water may have entered the EEC-V relay harness. Sometimes the relay is not clipped in place and it will just lay on the fender well. Then it can fill with water and malfunction.
      Don’t forget about the hall effect pick-up in the distributor; if this malfunctions you have a “no spark” condition.
      Rule out the EEC-V relay first. If you’re not sure buy one and install it, they are pretty inexpensive.

  6. Harry says:

    Hey I’m driving a 2004 Chevy Aveo. As I was leaving work today, I heard a sort of clatter, like something fell to the ground. After this, I kept hearing like a slapping sound which got louder as I pressed down on the gas pedal. After driving a few more blocks, the slapping sound stayed consistent, it wouldn’t get louder as I pressed the gas. The car also wouldn’t accelerate. I drove it on idle into a nearby parking lot after which the car shut off. It wouldn’t turn back on. The car tries to start but it won’t actually start running. I checked the belts which looked fine. I also tried checking the fuel pump. It sounds like it won’t turn on when I turn the keys into accessory mode.

    Any advice or ideas? Thanks!

    • ChiltonDIY says:

      Hi Harry. The 1.6L Aveo timing belts should be replaced at 60,000 miles, did you replace yours? I have read that some belts have broken before the 60,000 miles. I hope that’s not what is wrong, but it could be. If the timing belt breaks it will bend the engine valves. If the belt breaks the engine will usually turn over very fast and easily since there is no compression. That may have been the noise you heard.

  7. Danielle says:

    Hi! I have a 2000 Ford Taurus with a 3.0 L V6 duratec engine. Recently I have been experiencing some problems starting the vehicle. When I turn the ignition to the on position I hear a quick whining sound which I assume is the fuel pump? When I attempt to start the car the engine turns over, but fails to start. Usually on the fourth or so attempt it starts and seems to run fine (no check engine light or rough idle), but yetserday when I left fpr work it was idling rough and the check engine light came on, but when I returned from work the car immediately started with no problems and no check engine light. The damn car is so inconsistent I don’t know what to think anymore. Do you have any suggestions what this might be?

    • ChiltonDIY says:

      Hi Danielle.
      Scan the Taurus for diagnostic trouble codes. If the problem is only on start up it sounds like an idle control problem. The idle air control (IAC) valve controls the idle speed of the engine. At idle the throttle plate is closed. The IAC is computer controlled and allows only a certain amount of air around the throttle plate. This metered air controls the idle speed.
      Ford issued a technical service bulletin, or TSB for an IAC valve issue. “No start, hard to start, rough idle, intermittent check engine light” are some of the possible symptoms. The TSB, #03-3-5, is available with your ChiltonDIY subscription for your 2000 Taurus.

  8. glo says:

    Hi,
    I just bought a 1986 monte carlo with a 4.3 fuel injected engine ,it runs and drives but after it warms up whenever i get to a red light or stop sign it stalls out ,and when i try to turn it on again it sounds like its flooded sometimes it turns right on other times it takes a while,

    • ChiltonDIY says:

      Hi Glo.
      I would check for vacuum leaks and check the fuel filter and fuel pressure. Scan for diagnostic codes. Inspect and clean the throttle plate along with the idle air control (IAC) valve. (Keep cleaners away from the TPS sensor.) Inspect the exhaust gas recirculation (EGR) system; the valve could be sticking. Check the vacuum hose routing, especially for the manifold absolute pressure (MAP) sensor.

  9. Jon-Luc says:

    I have a 92 Honda Accord. Yesterday, I was driving when my car suddenly slowed down and decided to turn off. Luckily I was able to pull off the street before it died completely. I’ve also had the problem of whenever I want to go somewhere during the day, my car will crank but not turn over. If I let it sit for hours and come back, itll work just fine but starting yesterday it would just die on me when Im driving. The battery is fine (I don’t know about the alternator). The car works just fine when its cool out, like in the morning or night. I don’t want to pay for an alternator or a fuel pump assembly if I don’t need to. I just don’t know if this is common.

    • ChiltonDIY says:

      Hi Jon-Luc.
      Honda Accords did have distributor problems for that year. With the engine running, does the distributor make a scraping noise that can be heard above all the other engine sounds?
      It sounds like an ignition system problem.
      Note: The ECM has a main relay that can cause problems.
      Honda issued technical service bulletins (TSBs) and a Product Update/ Recall about the distributor issue to its dealers. In December 1995 Honda also sent a letter to Accord owners to notify them about the Product Update/ Recall.
      You can find the TSBs and Product Update/ Recall in your 1992 Honda Accord subscription. Though you will want to check all of the TSBs and Recalls for your vehicle, to narrow your search for this issue, use the keyword: “distributor” in the TSBs section.

  10. eric says:

    i have a 2010 jeep grand cherokee laredo. im not sure if the low grade gas here has cause a fuel system problem but the jeep starts rough and runs high rpm. it feels like the vehicle is starving of fuel but i really dont know. i have run fuel system cleaners through it but have not helped. the only thing i can think of is that my fuel pump may be going bad. any help would be greatly appreciated. thanks

    • ChiltonDIY says:

      Hi Eric.
      Scan the Jeep for related trouble codes. Check the fuel pressure if it feels like it is running out of gas.
      Find the correct fuel pressure specification in your ChiltonDIY subscription. Two fuel filters are used and are in the tank. One is located at the bottom of the fuel pump module. The other is located inside the module.

  11. Brandon W says:

    I have a 2005 f150 and yesterday I had it in some mud and it stalled out and then I started it back up and it ran fine like nothing was wrong and then I got to my house shut the engine off and walked inside and came straight back out and started it it ran fine no missing or anything and then about 30 minutes later I pulled in a parking lot to wait on someone and it was off for about 10-15 minutes then I started it and it had no problem but then I pulled out and it would go and then get really weak and then go again and it kept doing it and then I parked it for a few hours and then it wouldn’t even start so this morning it started and idled fine but it was still giving power and then shuting off while I was going down the road. and last night when it wouldn’t start I checked the bleeder valve for the fuel and it had not fuel pressure.

    • ChiltonDIY says:

      Hi Brandon,
      Did water and mud get into the engine compartment? It could be wet, which could cause the ignition wires to malfunction.
      Scan for diagnostic codes.
      If you suspect the fuel pump check the pressure with a gauge. Start with the basics: check the spark plugs, spark plug wires and the fuel and air filters.

  12. Lasha says:

    I have a 2004 impala in my car don’t be waiting to start in when it do start i have a back fire so i have been told that i need a new fuel pump in i have been reading up on it and i see same signs so its time for me to get it fixs

    • ChiltonDIY says:

      Hi Lasha.
      Check all the basics: the spark plugs, filters, ignition wires, and ignition coils. Scan the vehicle for related diagnostic trouble codes. Check the fuel pressure and compare it to the specification for your specific vehicle using the vehicle identification number (VIN) code or engine.
      There are two technical service bulletins (TSBs) from General Motors for your 2004 Impala that may apply to your situation: TSB# 02-06-03-008D and TSB# 03-06-04-030F. The TSBs are in your ChiltonDIY subscription for your 2004 Impala.

  13. David Weaver says:

    Hi I have a 99 F-250 Light Duty with the 5.4 and the last few weeks I’ve been having trouble keeping the truck running.it takes me 4-5 times to start it but it shutsdown on me but the only way i can keep it running is to stay on the pedal.after that then the truck stays running could this be the regulator or the little fuel pump in the tank.

    • ChiltonDIY says:

      David, it could be, but it could be a few other problems as well. Check the fuel pressure with a gauge to be sure.
      The correct fuel pressure specification is in your ChiltonDIY subscription for your 1999 Ford F-250, you can use the navigation outline following this PATH: Engine Mechanical > Specifications > Gasoline Engine Tune-Up Specifications.
      Scan for trouble codes, they may help in your diagnosis. If the problem is only present at start up you could have a faulty idle air control (IAC) valve.

  14. Tanya says:

    I have a 2001 Kia Spectra. My husband ran out of gas yesterday. He walked and got gas and it still wouldn’t crank. He filled it half full and still wont crank. A friend of his sprayed starter fluid in it and still wouldn’t crank. Changed out spark plugs and still wont crank. Can’t hear the fuel pump buzz when you turn the ignition on. Does that mean it’s the fuel pump?

    • Tanya says:

      OK later today we turned the key and we could hear the fuel pump buzz but still wouldn’t crank. My husband put a new filter on and still wouldn’t crank. Checked fuses, checked relays and all was fine. He put a new fuel pump on and it STILL won’t crank. Sputtered a few times but that’s all. What else can it be?

      • ChiltonDIY says:

        Hi Tanya.
        Use a fuel pressure gauge to check the fuel pressure.
        Also check to see if you have good spark on all 4 cylinders. Install one of the old spark plugs on the plug wire and ground it to the engine. Make sure the new plugs are in the cylinder head. Check each cylinder for spark with one of the old spark plugs. You need to make sure you have good hot spark from the ignition system and proper fuel pressure.
        Has the timing belt been replaced? If the timing belt slipped or broke the vehicle won’t start.
        What size engine do you have?

  15. Tanya says:

    I’m not sure what size engine. We put it in the shop. The timing belt broke. $500 to fix it. plus $50 towing. All the money we spent on the new spark plugs, fuel filter and fuel pump was a complete waste. Thanks for your help!!

    • ChiltonDIY says:

      You are welcome. Good luck Tanya.

      • Tanya says:

        OK the mechanic just called and said “it dropped a couple of valves”. I don’t even know what that means. He said he would call in the morning and let us know how much It will be to fix them. Nothing is ever simple.

        • ChiltonDIY says:

          Tanya, when the timing belt breaks in an interference engine, the engine may suffer extensive damage. The pistons will contact the valves, bending the valves, rods and possibly causing damage to the pistons. This means the cylinder head will need to come off to inspect the damage caused by the broken belt.

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