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!

849 responses to “How To Tell If Your Fuel Pump Needs Replacing”

  1. Joseph Edwards says:

    Hi Chilton DIY
    I have a 1998 mercedes benz c230 that dies when I turn it on. It wll stay alive for a couple secondes then start dying out. I replaced the fuel filter, but I didn’t put premuim fuel in the tank. Could that be the issue why the car dies out, because if it starts that mean that either the engine gets spark so the problem would be either air or fuel related. right? This is Joseph needing alot of

    • ChiltonDIY says:

      Joseph I don’t think that not using premium gas is your problem. Was the problem present before you changed your filter? Make sure you have good spark and check the fuel pressure. Check the fuel pressure under three different conditions:

      • without vacuum applied
      • with vacuum applied
      • retention after 30 minutes

      Mercedes specifies a different range for each of the three fuel pump pressure checks. You will find the correct specifications for your 1998 Mercedes Benz C230 in your ChiltonDIY subscription.
      You would also want to scan the vehicle for diagnostic trouble codes (DTCs).

      • Joseph Edwards says:

        Hey ChiltonDIY
        Do you think it could be the fuel pump. Also, if the fuel pressure is messed up could it be because of a short. I did attempt drain the fuel but the fuel pump would make the buzz sound and no fuel would come out.

        • ChiltonDIY says:

          Joseph did you install the fuel filter correctly? There is “in” and “out” marked on the filter.
          If you energized the pump correctly and no fuel was pumping you may have a faulty pump.
          Did you have the problem before you changed the fuel filter? Do you think you may have shorted out the pump when trying to energize it?

  2. Felix says:

    I have a 97 civic and ive been driving with a studder,it turned off at times but eventually it turned on again.i changed the gas filter and it stoped for a few weeks and now it did it again but now it wont restart.what is the problem?

    • ChiltonDIY says:

      Felix, first remove a spark plug wire and with a spark tester or screwdriver check for a hot spark. Do you have spark?
      Next check the actual fuel pressure. If you scan the Honda Civic for diagnostic trouble codes (DTCs) it could help you pin down the problem. As a general rule you should scan for any related diagnostic trouble codes. That’s assuming you have a scan tool.
      If spark, fuel and DTCs are fine, next check out timing and compression.

  3. MelonyB says:

    I have 2004 VW Jetta. Can anyone tell me if the fuel pump goes out will it cause the coil pack to go out also?

  4. Annalee says:

    I own a 2000 dodge caravan se I drove the car to work the other day and it drove fine.when I got to work the engine began making a spluttering noise and died..restarted the vehicle and the engine splutter and died again..went to restart it a third time an it won’t acts like it wants to but won’t and when I press the gas pedal nothing happens it does not rev up..fuel pump? Filter? Or something else?

    • ChiltonDIY says:

      I would scan the Caravan to see if any codes are present which may help you diagnose the problem. By codes I mean diagnostic trouble codes or DTCs.
      Check the fuel pressure and inspect the ignition system. Do you have good hot spark? Are the ignition plugs and wires okay? What size engine do you have?

  5. Ken says:

    I have a 93 Cadillac Fleetwood Brougham with a 350 chevy engine. It will start then shut off a few minutes later and can only be refired by priming the carb with gas or starting fluid only again to shut off after a few minutes. It runs smooth and there is no lack of power. It seems to just run out of gas (which it isn’t). The pump activates when the key is turned on. I’m thinking maybe a fuel regulator. If a relay overheated, would it not correct itself when it cooled down? Any suggestions would be appreciated.

    • ChiltonDIY says:

      Hi Ken.
      I would test the actual fuel pressure with a gauge to see what the pressure reads. If the relay went bad the fuel pump would not energize at all. Have you scanned the Fleetwood for related diagnostic trouble codes (DTCs)?

  6. Patricia G says:

    I have an 82 VW Rabbit Convertible that will not start., When I turn the key I hear a boom noise. I was having problems last week with it trying to die on me any suggestions?

    • ChiltonDIY says:

      Patricia, by “boom noise” do you mean exhaust backfire?
      How are the ignition components, spark plug wires, distributor cap? Has it been wet where you live? Faulty ignition parts can cause a backfire boom noise.

  7. latese s says:

    Hi I have a 2000 Pontiac Grand Am the fuel pump went out on it I replaced it with a new one it ran for that 1 day but then the next day it wouldn’t start again, I replace the fuel injectors I replace the fuel filter just started for a day or two then wouldnt start again, but if you spray starter fluid in the car it starts right up, and some days it might even start up for 4 days straight and then just go out again. My mechanic say it is a fuel related problems so do you think I should change the fuel pressure regulator now or could it be some thing else? Thanks in advance!

  8. latese s says:

    Here is more details about the day that I replace the fuel pump I was driving it I was doing like 35 miles per hour and then all of a sudden it just slowed down to like 15 miles per hour like it wasn’t getting any gas, and then seconds later it just took off and started back to drive normal and like I was saying some days it will start up 3, 4 days straight and then go back out the next day and it wont start for like 3-4 days and then all of a sudden she’ll start back up. Help me Please!

  9. Andrea says:

    Hi! I have a ’95 jetta that died on the way home from work last night. When I turn the key all the lights turn on as usual, but the engine does nothing. Also, the hazards reset themselves and blink for two minutes. This usually happens after the battery dies. I put gas in a few hours before, but when it died it felt as if it had run out of gas. Do you think it is a bad fuel pump? Thank you for your help!

  10. Larry says:

    I have a 2002 Ford Explorer flex fuel V6. It’s not getting any fuel to the engine. I can here the fuel pump turn on. I have replaced the fuel filter. I have checked the fuel pump relay and the fuels. I have pushed the emergency fuel shut off button to see if that was the problem but it wasn’t. Checked for leaks in the fuel line found none. Don’t know what else it could be. Please help.

    • ChiltonDIY says:

      Hi Larry.
      If you hear can hear the fuel pump run and the fuel pressure is not at specification, I would suspect a faulty fuel pump. The testing port should be found on the fuel rail. If you don’t have a gauge, remove the front connection of the fuel filter. Install a pan or bucket to catch the fuel, then cycle the ignition switch to see if fuel comes out the open end of the fuel filter.
      Check your ChiltonDIY subscription for your 2002 Ford Explorer’s fuel pump specification by following this PATH: Engine Mechanical > Specifications > Gasoline Engine Tune-Up Specifications.

  11. selene says:

    How would you know if you need a fuel pump or fuel filter after reading I think its a fuel pump but it could be a fuel filter too.

  12. selene says:

    Also when you start your car if you dont hear the buzzing sound does that mean your fuel pump is bad

  13. ashley says:

    Hi I have a 98 town and country that ran out of gas recently. We put some gas in it today and when trying to start it sounds like it isGoing to turn over but doesn’t. When turning the key to the on possition the pump kicks on some times but not everytime if you tap on the gas tank and then try to start the van it will start.

    • ChiltonDIY says:

      Ashley, it sounds like you have a bad fuel pump. By tapping on the fuel tank sometimes you can jar the fuel pump motor and it will start pumping fuel. This is and old trick that sometimes works. If the vehicle started after tapping on the fuel tank, I would replace the fuel pump assembly. If you install a fuel pressure gauge to your van you can actually watch what happens when you tap on the tank. A fuel pressure gauge is an important tool for a correct diagnosis of the fuel system.

  14. Chris F says:

    I am having a problem with my honda s2000 starting. It is intermittent and only occurs on the first start of the day. The engine cranks but will not turn over and start. Once this occurs I am not able to start it for the rest of the day, but when I try to start it the next day it starts up. The battery has been replaced and the starter and alternator have been tested and appear to be fine. There is a check engine light on for the secondary air pump, however this came on a little over a week after the problem started. I have taken it to a third party and they believe it is the fuel pump that is the problem but are not sure. I took out to Honda and they think it is the secondary air pump. It is $650 to put in a new fuel pump and $1500 for the air pump. Don’t think it is the air pump as others have actually taken it out and put a simulator in. Seems not vital for starting or engine function. The car is stock except I replaced the air filter with a k&n. Need some help as I fear I will drop the money and the issue won’t be fixed. It is a 2004. Let me know if I need to provide any additional information. Pretty new to this so wanted to hear what y’all think might cause this. The fact that it is intermittent is curious to me. Thanks.

    • ChiltonDIY says:

      Hi Chris.
      Intermittent problems are more common than you think and can be frustrating to diagnose. Sometimes repair shops will ask you to leave the vehicle for a few days. That way they can check the vehicle hopefully when it won’t start. They will test the fuel pressure, check for spark and communicate with the vehicle’s computer.
      The PGM-FI main relay controls the fuel pump. On older Hondas the main relays would go bad and cause intermittent starting problems. The s2000 does have a problem with the manifold absolute pressure (MAP) sensor, but this problem usually occurs during heavy acceleration. I would still check the sensor and connector. I’ve seen faulty MAP sensors cause hard staring conditions.

  15. Trish says:

    Hi I have a 2001 Nissan primera. It runs sluggish..when slow down and put foot on gas feels as if it jerking. Then tonight was driving home and it felt like it was running out of has half tank gas. Can please help??

    • ChiltonDIY says:

      Trish, I would scan the vehicle for related diagnostic trouble codes (DTCs). By scanning the Primera you may be able to pinpoint the problem: Fuel or Spark.
      Check the actual fuel pressure with a fuel pressure gauge. Inspect the ignition components: spark plugs, coils, wires and/or boots.

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