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!

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

  1. DANIEL ROOT says:

    i have a 92 mark 7 i know the fp is working as i did the appropriate test’i have no power at the power supply i’ve checked the relay and it seem’s to function ok i know the pcm could be the culprit but i want to eliminate all other cause’s i started the car to warm up and 5 minute’s later it just died it’s been running excellent with no sign’s of a problem any chance you have an or multiple idea’s any help would be appreciated thank you for your time

    • ChiltonDIY says:

      Hi Daniel.
      Have you checked the fuel inertia switch? This switch shuts off the fuel pump in the event of a collision. Once the switch has been tripped, it must be reset manually in order to start the engine. The inertia switch shuts off the fuel pump power.
      The inertia switch is located in the trunk behind the side panel.
      You can read more about the fuel inertia switch and view photographs and drawings of it in your ChiltonDIY subscription for the 1992 Mark VII. Search for “inertia” or follow this path using the navigation outline:
      PATH: Fuel Systems > Gasoline Fuel Injection System > Inertia Fuel Shut-Off Switch

  2. Aley says:

    Hi , my question is I have a 04 VW Beetle turbo convertable. About 6 months ago the car would start and than die within seconds of
    Starting . The fuel filter was replaced and the car started right up and had no problems. 2 months ago the car started to started up fine and intermittently would die after 2 seconds if starting , but the second turn over the car would start up . Just recently the car will start up but yet again die within 2 seconds of starting . The fuel filter has been chagrd and it still will not stay on . When you turn the car to start you can hear the fuel pump turn on . The dash shows the check engine light and a light that says EPC . Any ideas ? We seem to think it the fuel pump what do you think ?

    • ChiltonDIY says:

      Hi Aley.
      I would first scan the Beetle for diagnostic trouble codes (DTCs). The check engine and the EPC lights are on because the vehicle’s computer detected a problem and has set a code. Retrieving the diagnostic codes should give you an idea whether it is a fuel problem or not. (The EPC light is the Electronic Power Control warning lamp.)
      I wouldn’t replace the fuel pump until you do more diagnostics. Have you checked the fuel pump running pressure? What size engine do you have in the Beetle?

  3. Adrianna says:

    I have 2002 Saturn SL2 and the only way I can get it to start is to step on the gas. Can That indicate the fuel pump is bad. I turn the car to on and i hear something not sure if its the fuel pump though. If I keep it in on for like 20 seconds then it will start no problem.

    • ChiltonDIY says:

      Hi Adrianna.
      It sounds like you might have a cold starting condition. I would scan the vehicle’s powertrain control module (PCM). The SL2 may have set a diagnostic trouble code (DTC), which could help identify your problem.
      Try cleaning the throttle body and the idle ar control valve. Sometimes just cleaning the throttle body can help.

  4. Tori says:

    I have a 2002 Pontiac grand am and I have a problem withit stalling. In the beginning of winter it would stall whenever iI stopped at a red light or stop sign, it would usually start back up but stall again at the next stop. I had a new fuel pressure regulator put in and it was fine for a week ran like new then even when I hit the brake it would stall. Sometimes its perfect sometimes all it wants to do is stall. What do you suggest be replaced?

    • ChiltonDIY says:

      Hi Tori.
      Tori, I would scan the Grand Am for diagnostic trouble codes (DTCs).
      Take a look at the idle air control (IAC) valve. The IAC valve controls the idle for your Grand Am.
      GM issued a technical service bulletin for an intermittent stall that may relate to the concern you have with your Grand Am. Technical service bulletins (TSBs) are part of your subscription to ChiltonDIY, use the filters to speed your search.
      Which engine does the Grand Am have, a 2.2L or 3.4L?

  5. elvis lopez says:

    Please help! I have a 1993 acura integra.I turn on my car it warms up and when I put it on “D”drive, it slowly turns off like if it was an old bunky car.It has a new engine and a new transmission.What can be the problem?

    • ChiltonDIY says:

      Elvis, the Integra could have a faulty electronic air control valve (EACV). Scan the Integra for DTCs to help diagnose the stalling condition.
      The EACV controls the amount of air bypassing the throttle plate in response to signals from the ECU (electronic control unit). During certain conditions, such as cold engine operation, when the air conditioner compressor is engaged, the automatic transaxle in gear, or the alternator is charging, the EACV is energized to control the idle speed correctly. The EACV is controlled by the ECU proportional to engine coolant temperature. Integra engines incorporate an additional vacuum-operated air boost valve to provide more intake air during cranking.
      All vehicles except the Integra with a manual transaxle also employ a fast idle valve. The Integra with the automatic transaxle controls this valve electrically through the ECU; all others are controlled by a temperature-sensitive thermowax valve reacting to the coolant being circulated through the valve body. On a cold engine, more air is admitted into the engine, raising the idle.
      Note that in all cases, the external idle adjustment screw acts on an air-bleed passage, not on the throttle mechanism.

  6. Tia says:

    Hi, I have a 2002 jeep liberty. I filled my car gas the dte (drive to empty)say 190 miles. I drive 4 miles and it say 175 miles ? I just had spark plugs change, new air filter,and oil change last week. any suggestions is helpful. Thank You

  7. Juliana says:

    I have an ’87 BMW 325. A couple days ago the car wouldn’t start up. I let it sit for a few minutes then it started up and I was able to drive off. The following day while driving it stalled on me and it wouldn’t start back up. I had to have someone help me push it to park. Then this morning it started up again (but I didn’t drive it.) I had someone who did the test you mentioned where I put the key in the accessory position and he checked under the car. He said it was the fuel pump (nothing came on.) But I haven’t had someone try the fuel pressure gauge test. Since it stalled completely while driving, do you think it is likely the fuel pump needing to be replaced, or could it possibly be some of the other things you suggested such as the fuel pressure regulator or obstruction in the fuel line needing to be cleaned out, etc. I also noticed that while driving it was making a buzzing sound that was getting more apparent. Thanks for any advice.

    • ChiltonDIY says:

      Hi Juliana.
      If the buzzing noise is coming from the fuel pump, check the running fuel pressure. Leave the gauge installed and run the vehicle until the vehicle shuts off, check the pressure reading.
      The correct fuel pressure for your 1987 BMW 325 is in your ChiltonDIY subscription. Follow this path from the navigation outline: PATH: Engine Mechanical > Specifications > Gasoline Engine Tune-Up Specifications. Your fuel pressure specification is on the third page of the specification table.

  8. Sasha says:

    My 2001 ford mustang v6 base model has those exact symptoms. I had a neighbors who are a family full of mechanics check it out and they told me its most likely the full pump, they did the noise check. and trouble shooted everything else they could with some minor tools at hand. My question is, is there any way to fix a fuel pump by hand in front of your house without any heavy duty equipment(Jacks and anything else big you would find in an engineers shop). Just your basic tools like wrenches, screw drivers,etc. Or is this a job that can only be done by lifting the car up in a shop. Just asking this because I highly hope I wont have to pay for a towing service.

    Thanks so much for the article.

    • ChiltonDIY says:

      Hi Sasha.
      The Ford Mustang fuel tank can be removed with a jack, jack stands, fuel container, and basic hand tools. The only special tool you may need would be a fuel line removal tool. You can purchase one at the parts supplier if you need it, they are not very expensive.
      You will need to jack up the vehicle high enough to remove the fuel tank, that’s the hard part. Carefully remove the lines, straps, fill tube, EVAP (evaporative) hoses and electrical connector.
      You will also need to use caution and patience, remember you are working around GASOLINE! Always have a fire extinguisher nearby!

  9. Lisa says:

    I have a 2002 pt cruiser touring. My daughter was driving and it just shut off and would not restart. Had it towed home and I listened for the fuel pump to hum and it does. What else can I do to check for a fuel problem? Dont want to spend a lot of money for unnecessary reasons. Thanks in advance.

    • ChiltonDIY says:

      Lisa, check to see if you have hot spark at each spark plug, remove the plug wire install a spark tester or old spark plug. Ground the spark plug at the engine. Turn over the motor and check for hot spark at each wire.
      Maybe the timing belt has broken. Have you had the timing belt changed. This will cause the engine to shut off and cause damage to the valves and possibly the pistons. When this happens the motor will spin very fast and easy when trying to start the engine.

  10. John says:

    I removed fuel filter inline crank over engine. Got no fuel to come out. It is a electric fuel pump on 2001chevy truck this means fuel pumps bad

    • ChiltonDIY says:

      Hi John. it sounds like a fuel problem. Make sure you have fuel in the tank. GM does have problems with the fuel gauge sending units reading 1/4 tank when they are actually empty.
      Make sure you are getting current to the fuel pump before you replace it. If needed check the fuse, ground and fuel pump relay.

  11. Meeka says:

    I have an older Ford Explorer, 1999. The car at times acts like it doesn’t want to start but if I wait 5/10 sec and try again it starts. A mechanic said it’s a common issue with the Ford truck, said I can replace the pump or live with it. Again sometimes but not all times while getting onto the freeway the car seems to slightly jerk or lose power going up the ramp. Is this due to the fuel pump issue and can the pump suddenly go out?

  12. Meeka says:

    if there is no check engine light on, will a diagnostic test show anything wrong with the fuel pump or anything else for that matter?

    • ChiltonDIY says:

      Hi Meeka.
      Yes the fuel pump can just stop pumping, usually they tend to fail when you stop the vehicle and the pump cools down.
      As far as setting the check engine light, sometimes codes are stored in the vehicle’s history and might not set the light. I would scan the vehicle and check.
      Sometimes when a vehicle manufacturer finds there is an issue with a component they will send a notice to their dealer technicians about it in order to repair vehicles more quickly. These notices are called technical service bulletins, or TSBs for short. There are a couple of TSBs about your vehicle for the fuel pump and the sending unit. You can find the TSBs and Recalls that Ford issued for your 1999 Explorer in your ChiltonDIY subscription. Speed your search by using the filters, for example, filter by the system: Air and Fuel Delivery.

  13. Phillip W Ashington says:

    Word to the wise, please use some type of protective lenses when performing this type of maintenance. One of my buddies, owned an auto body shop and lost an eye doing an oil changes without his glasses on.

  14. Michelle says:

    I have a 97 Mercury Grand Marquis. It has been acting up and I’m trying to figure out the cause with as little waste of money as possible. It seems to act up when sitting at a light or stop it will rev like it wants to take off every now and then, but then at other times it won’t do thatn instead when I go to take off from a stop it will kinda jerk and act as if its power is in spurts. Sometimes it will last a few seconds with no acceleration but a rev and sometimes it will just jerk until almost a complete stop. I will shut it off and it will start up and drive just fine again. It will struggle to start , I will shut it off and try again and the second time it will start right up. Today, It decided to take of jerking after a stop, I stopped, turned it off and it gave me trouble starting as if it would start and ikmmediately die, did this a few times, gave it a break and it started up and drove home without further issue. Any and all help is so much appreciated. Thank you in advance.

    Michelle

    • ChiltonDIY says:

      Michelle, I would check the fuel pressure. It sounds like a fuel problem, so have the fuel system checked. You’ll find the correct fuel pressure for your Grand Marquis in your ChiltonDIY subscription in the Fuel System, under Gasoline Fuel Injection and then Fuel Pump, Testing. Scan the Grand Marquis for diagnostic trouble codes (DTCs).

  15. Jim says:

    My ’99 Toyota Tacoma had been idling rough at start-up; I had to “feather” the throttle for about 30 seconds before the idle smoothed out…and then the truck would run fine. Yesterday, after the usual “feathering” process, the engine idled smoothly, but will not rev above 1800 rpms. When I try to raise the rpms, the motor loses power. I checked all the vacuum lines (all that I could find, anyway) and replaced the PCV valve…problem remains. Could the fuel pump be the problem? I tried the key test, and don’t hear anything from the pump, but the truck starts right up, and after feathering the throttle, idles smoothly. Would it continue to idle with a bad fuel pump? Thanks for any suggestions!

    • ChiltonDIY says:

      Hi Jim.
      If it is a fuel pump problem I would be surprised. Is the check engine light on? Scan the Tacoma for DTCs (diagnostic trouble codes) it might help point you in the right direction.
      Check to make sure the air bellows after the mass airflow sensor (MAF) are not leaking. An air leak between the intake hose and the MAF will cause problems.

      • Jim says:

        Thanks for pointing me in the right direction– my air intake had become separated from the air-filter box; irregular air-flow and a dirty MAF were causing the problem. A good spray-cleaning of the MAF and securing the the seal on my air-intake has got the ol’ “Green Hornet” running like a top! THANKS AGAIN!!!

  16. Rob says:

    I have a 99 Mercury Cougar 2.5L v6. It has been sitting for about 6 months. I replaced the battery which was bad and have only been able to get the engine to fire with starting fluid. When i do this i can keep it running as long as i continue to spray. I checked the inertia switch which was fine. When I turn on the ignition to listen for the fuel pump I do not know If i hear it or not due to the wind (im stuck outside) and the beeping of the dash. I can start the car for roughly 2 seconds before it shuts itself off. Im not sure of the next step to take to diagnose. I have no way of getting this car someone where to have the codes read.

    • ChiltonDIY says:

      Rob, it sounds like a fuel system problem. You will need to check the fuel pump relay operation.
      If the relay is okay check the fuel pump module connector pins.
      Check to see whether you have the correct voltage supplied to the fuel pump and check the ground circuit. Fuel pump testing and voltage specifications are in your ChiltonDIY subscription for the 1999 Cougar. Follow this path: Fuel Systems > Gasoline Fuel Injection System > Fuel Pump > Testing.

  17. Patrick says:

    My 1999 Mountaineer/Mercury 5.0 sputters and shuts down when idling. Sometimes it will not respond when gas peddle is depressed. These symptoms happen when gas level is at quarter of a tank or less. When I fill tank to half a tank or more the symptoms rarely occur. Could this be a sign that the fuel pump is faltering?

    • ChiltonDIY says:

      Patrick, Ford issued a technical service bulletin for your Mountaineer’s exact problem.
      In your ChiltonDIY subscription go to “TSBs” and select the symptom: “Engine won’t start.”

  18. Monti says:

    Hi. Glad to find a knowledgeable person. 2000 explorer Eddie baurer. The interia switch never tripped. When I turn on the ignition and hear the fuel pump engage the engine will start. When I turn on the ignition and do not hear the fuel pump the engine will not start. I also have a battery that I don’t have confidense in. Changed the alt but it still goes dead. Even fully charge the pump is hit or miss with engagement. Is the pump going bad and is it possible it’s not receiving enough power to engage.

    • ChiltonDIY says:

      Hey Monti, first and foremost the battery has to be 100% charged. I would check the battery and charging system. Have a load test performed on the battery! Low voltage can play havoc with your entire vehicle, especially relays. I have seen people waste time and money searching for a problem that was caused by a faulty battery.

      • Monti says:

        Ok. I will stay in touch . Its sort of a scramble. I had an thermostat housing an alt. a battey all go bad almost simultaneously. Now a possible fuel pump? Could that leaking housing cause this much mayhem considering relays? It was the first problem in order. Thanks. Love this site and your people

  19. Clay says:

    Hi,
    I have a 1997 Infiniti I-30. Started one day, the next day went out to start it, it turned over but will not crank (start). Wondering if it is the timing belt (as an independent mechanic surmised) or maybe the fuel pump. Even when the car would start it often would do so rough. And while it idled there was a squeaking sound under the hood. Sometimes when I would hold the pedal down for a second, the car would have smoother start. Can the timing belt go when you’re not driving the car but when you try to start it? I’m stuck, trying not to spend a bundle on a timing belt if maybe its just an issue with fuel not getting up to the engine.
    Thanks for any guidance you can offer! Clay

    • ChiltonDIY says:

      Clay, your Infiniti has a timing chain not a timing belt. I would check the squeaking sound, see if the noise is coming from the engine (timing chain area). This squealing may be related to your problem. Try scanning your I30 for DTCs (diagnostic trouble codes), this may help point you in the right direction.
      Then test the fuel pressure, check for hot spark at the ignition coil(s). Check the timing and compression.
      Infiniti issued a technical service bulletin (TSB) about a timing chain noise, it is in your ChiltonDIY subscription. With more than 100 TSBs for the I30, find it fastest by sorting by System. Select “Engine.”

  20. Jasmine says:

    Okay, I literally know nothing about cars and I’m not understanding anything I’ve read online so far… I have a 2011 Honda Civic and I just got it towed because it was turning over but not actually starting. All I’ve been able to gather from what I’ve read online is that it’s probably something to do with a fuel pump. But, my question is it normal to have a problem with a fuel pump (whatever that is) with a car that’s barely 3 years old?

    • ChiltonDIY says:

      Jasmine, it would be very unusual for your Honda to have a bad fuel pump. Do you use good quality gasoline (name brands)? It’s possible the filter which is inside the tank could be clogged. This can happen when using gas that has more impurities.
      Have the Civic scanned to see if a diagnostic trouble code (DTC) was set. This will be one of the first steps towards finding your car’s problem.
      How many miles do you have on your Civic?

  21. mike says:

    I have a 1997 gmc jimmy that sometimes wont start then after awhile it will start I hear the fuel pump running but its not pumping gas ,when it starts it runs good ?

    • ChiltonDIY says:

      Hi Mike.
      Mike, what engine do you have in your Jimmy? I’m assuming you have a 4.3L W engine? Follow the diagnostic routine in your ChiltonDIY subscription for the 1997 Jimmy by using this path from the navigation outline: Diagnostics > Diagnostic Routines > Powertrain > Engine Controls – 4.3L > Fuel System Pressure Test
      Have you tried scanning the Jimmy for DTCs (diagnostic trouble codes)? I would. You need to determine whether it is a fuel or spark problem. Have you checked the fuel pump harness connections and the fuel pump relay?

  22. Sean says:

    I have a 1995 geo prizm base model 1.6. Recently and randomly it started sputtering when accelerating from a stop. It won’t sputter everytime and sometimes it will die. My engine will get very hot if I drive it for long even though my in dash thermostat shows medium heat. Yesterday I replaced the spark plugs, wires, distributor, rotor, fuel pump and cleaned out my throttle body but it made it worse. After my car superheated while test driving and died I decided to take out the thermostat and now it’s running fine without it. Could that mean I needed a new thermostat because it was stuck closed?

  23. ChiltonDIY says:

    Hi Sean.

    Yes you are correct in thinking it’s the thermostat. I would replace it.
    Check the fan operation on your Prism after you replace the thermostat. Make sure the fan comes on at idle after the engine reaches operating temperature.
    Don’t forget to line up the bleed valve on the thermostat as shown. The image shows the correct placement of the air bleeder valve during thermostat replacement

  24. rey says:

    I have a 2001chevy sliverrodo an it stalled on me like it will crank but when I put my foot on the gas it turns off

    • ChiltonDIY says:

      Hi there Rey.
      Scan the Silverado for diagnostic trouble codes (DTCs). This can help pinpoint your problem.
      Is it a fuel problem or secondary ignition? Make sure the fuel tank has gas. GM has had problems with some of their fuel gauge sending units. The vehicle may show 1/4 tank of fuel when it is actually empty.
      If you suspect a fuel problem, check the fuel pressure with a pressure gauge.
      Rey what engine do you have in your Silverado? Is it a 1500, 2500 or 3500?

  25. Michelle says:

    Just replaced fuel filter on 07 mustang the miles to E won’t reset , just filled up gas tank usually get 400+ MPT and now it says 268. Any ideas ??

    • ChiltonDIY says:

      Hi Michelle.
      Some Mustangs may have the malfunction indicator light on with a diagnostic trouble code, DTC P0463, or an erratic fuel gauge concern. This could be from fuel that is contaminated with sulfur. Sulfur will cause an open or high resistance on the fuel sender card leading to an erratic fuel gauge reading or it can cause the trouble code P0463 to set. Some ford Mustangs have had numerous problems with the sending units and fuel tank designs.

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