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. Tyler says:

    I own a ’93 Chevy Corsica. I was parallel parking and had it in reverse when my car suddenly died. I started it again no problem and finished parking. A short while later I started it again but it was shuddering slightly. It would hesitate starting up at red lights and there was a strong smell coming from the exhaust pipe. The next morning I got in and it wouldn’t even start. I replaced the fuel filter, thinking it was clogged. I’m not sure if it could be the spark plugs or the fuel pump. I’m hoping its not te pump, because I believe mine is inside the gas tank.

    • ChiltonDIY says:

      Hi Tyler.
      Yes, you are correct, the fuel pump is in the fuel tank. What size engine do you have? Have you had the vehicle scanned, it is OBD-I.

  2. joann aww says:

    Hello i have a 2002 dodge ram 1500 5.9 engine i replaced the fuel pump already and yesterday it turned on i pulled it up to my drive way and it turn off on me and tried to turn it on and it doesnt want to turn on know a red dot light is coming on what cant that be

    • ChiltonDIY says:

      Hi Joann.
      Check the fuel system; verify that the pump operates at the key on position. Check the fuel pump relay operation. If the relay does not operate, check for a blown fuse. Inspect the fuel pump for a leak-down condition. Test the fuel pressure, volume and quality. The correct fuel pressure specification is in your ChiltonDIY subscription for your 2002 Dodge Ram 1500. Test the operation of the fuel regulator.
      If the fuel pressure is good, then check the ignition system. Inspect the secondary ignition components for damage (look for rotor “punch-through”). Inspect the coils for signs of spark leakage at coil towers or primary connections. Check the spark output with a spark tester. The secondary ignition system includes the spark plugs and wires, the cap/rotor, and the ignition coils.
      Scan the vehicle for Diagnostic Trouble Codes (DTCs).

  3. Chad says:

    I have a 1999 Firebird 3.8L. It starts well and does not stall, but it will occasionally sputter and lose power for 10 to 15 seconds while driving. Then everything appears to go back to normal. It is throwing a “Random Misfire” code. The fuel pressure regulator, fuel filter, plugs, wires and coils are all fairly new. Does this sound like a failing fuel pump?

    • Chad says:

      One other piece of information: the last time this happened, I could smell something hot or burning afterwards.

      • ChiltonDIY says:

        Chad, if the system runs lean it can overheat the catalytic converter, this can cause a smell. Install a fuel pressure gauge and check the actual fuel pressure to be sure.

  4. Kenny says:

    I have a 2005 Dodge 1500 hemi 5.7L. Runs and idles fine but stalls periodically. Changed all 16 plugs, checked pcv valve but not sure how to check vacuum on this system.

    • Kenny says:

      Usually stalls on start up after I put it in drive.

      • ChiltonDIY says:

        Hi Kenny.
        At idling speed, an engine should show a steady vacuum reading between 17 and 21 inches of Mercury (in. Hg). A quick opening and closing of the throttle should cause vacuum to drop below 5 in. Hg and then rebound to 21 in. Hg or more.
        All the other systems in an engine must be functioning properly before you check the fuel control system as a cause for poor engine performance. If the pointer has a slow floating motion of 4 to 5 in. Hg you should check the fuel control.
        Vacuum readings will vary depending on the altitude. From sea level to 2,000 feet elevation normal engines should show a vacuum reading between 17 to 21 in. Hg. Above 2,000 feet elevation the vacuum reading will be about one in. Hg lower per each 1,000 feet rise in elevation.
        You can navigate to the engine vacuum tests for your 2005 Dodge Ram 1500 in your ChiltonDIY by following this PATH: Diagnostics > OBD System Information > Introduction > Where To Begin > Engine Vacuum Tests.

  5. jonathon s. miles says:

    I have a 88 s10 blazer 4.3l. On my way to work this morning driving about 35 through town my truck started surging. reving up then losing power. i just rebuilt the top end and replaced the fuel pump and filter. what could be wrong? Anything would help!!!!

  6. Sadel says:

    I have a 96 Nissan pathfinder and yesterday I had to go to store drop off my kid wait for them they came out in about 10 minute then the truck would not start I waited for 45 minute than start with a lot of hesitation it start when ever I go it does not shown sing of weakness please help.

    • ChiltonDIY says:

      Hi Sadel,
      Nissan issued technical service bulletins (TSBs) that might apply, one is for high-altitudes and two are related to cold weather driving. You can find the TSBs and Recalls in your ChiltonDIY subscription for your 1996 Nissan Pathfinder.
      Scan the vehicle for diagnostic trouble codes (DTCs). Check the vehicle for codes when it won’t start, if possible.
      Check to see if you have spark from the ignition system. Check the fuel system pressure.

  7. Amber says:

    I have a ’96 Grand Voyager. If fuel amount ges around half tank, van will crank but die immediately. While driving with this amount, it sputters and acts as if it will stall out. Mashing gas petal to floor even has delay. What could be the issue?

    • ChiltonDIY says:

      Hi Amber.
      Test the fuel pressure and scan for diagnostic trouble codes (DTCs). A faulty ignition system or MAP (manifold absolute pressure) sensor could cause the same problems. Scanning the vehicle’s PCM (powertrain control module) for related DTCs will help you pinpoint the area of the problem.

  8. Michael says:

    Hi there!
    I have a 1990 oldsmobile cutlass supreme sl 4 door sedan. I am having some of the issues that are popping up on here and I have replaced the fuel pump relay so I think I need to take the next step of getting the fuel pump replaced. I am having hesistation when I press on the gas on occasion but when this problem it happens for a good week then fades away. I would like some input on what you guys think. Also my car has died multiple times when I have stopped at stoplights.

    Thanks, Michael

    • ChiltonDIY says:

      Hi Michael,
      First I would scan the vehicle for diagnostic trouble codes, or DTCs. Check the fuel filter and test the actual fuel pressure. Then if needed I would check the ignition system, vacuum readings, sensors, and exhaust.
      Has the check engine light come on? What size engine does the Cutlass have?

  9. Leon says:

    I have a 01 Taurus sometimes when I start it it doesn’t keep running. I have to drive it like a standard keeping my foot on gas and brake at the same time after a few minutes it runs normal. Yesterday I was on the freeway the rpm dropped and it quit responding to the gas pedal then it turned off towed it hm the next morning it started up. Does this sound like the fuel pump out something else.

    Thanks, Leon

    • ChiltonDIY says:

      Hi Leon, it very well could be, check the fuel pressure. You’ll find the correct fuel pump pressure specification in your ChiltonDIY subscription for the 2001 Ford Taurus using the navigation tree by following this PATH: Engine Mechanical > Specifications > Gasoline Engine Tune-Up Specifications.
      Scan the vehicle for diagnostic trouble codes, or DTCs.
      How is the fuel filter, has it been changed in the last 30,000 miles?
      How about the spark plugs and plug wires?
      Rule out all of the service items first. When the ignition system malfunctions it can feel like a fuel problem.

  10. Payton says:

    Hey I drive a 96 toyota T100 that has a 3.4L fuel injected engine and it has trouble starting, it actually starts better when it is cold like in the winter after it sits all night but if I turn the engine off and wait fifteen minutes it struggles to start up. When it is warm (15min after shutoff) it sounds like the engine is turning over quickly, and on a cold start (winter 12+ hours after being shutoff) it turns over more slowly but starts up quicker (3-5seconds of turning the ignition) but still struggles. I mean it is pretty bad if I wait fifteen minutes I have to sit there and twist the key for about 9-15 seconds before it fires up, what could this be?

    • ChiltonDIY says:

      Hi Payton.
      Check the ignition timing, make sure it is not to far advanced. Advanced timing would cause a hard and slow cranking condition when hot. Then I would scan for diagnostic trouble dodes (DTCs), and if possible look at the coolant and air temperature readings. You will need a quality scan tool for that. Sounds to me like it might be a temperature driven problem.

  11. Jocelyn Elizabeth says:

    Hi, we have a 99 Dodge Durango. Im suspecting the fuel pump is going because this is very similar to when the that happened to my Tahoe years ago. I know we need something with the exhaust fixed (sounds like a motorcycle and smells rich), but I don’t know if these recent problems are related to that. The suv suddenly stopped running one night while my fiance was driving. he called me to tell me and i asked if he was out of gas, he said no, just low. So hours later after he tried everything i brought him gas and it started. We have since been keeping the tank as full as we can afford. last night we go drop all our money on a deposit for a house, get in the car and it won’t start, it tried so hard and sputtered like crazy, it just couldn’t stay on. I told him its just like what happened with my Tahoe. we sat for a while, then he banged the fuel pump n tank (a trick that worked with the Tahoe) and it stated just fine. we turned it off and on two more times that night noproblem. This morning i tried to drive it and it wouldn’t get on past accessory, no sputtering or anything. The pump sounded on though. Banged on the tank… started right up. My question iswhere should we start? What else could that be? Should i assume it is the pump or start trouble shooting with something else? We are very low on cash and can’t afford to try a bunch of things lol. I really hope you can give me an idea.Thank you so much!!

    • ChiltonDIY says:

      Hi Jocelyn Elizabeth,
      If you bang on the fuel tank and the fuel pump starts to run, that does sound like a faulty fuel pump.
      Check the fuel pressure to be sure. Remove the cap from the fuel rail test port. Connect a fuel pressure gauge. Though Dodge specifies an OEM tool to check the fuel pressure, a generic tool can be used. Adapters may be needed.
      Check your ChiltonDIY subscription to obtain the correct fuel pressure specification by following this PATH: Fuel Systems > Gasoline Fuel Injection System > Fuel Pump > Testing
      The fuel pump module is located inside the tank. This system has no external fuel filter.

  12. dan says:

    I changed the spark plugs in a 98 monte carlo and the fuel pressure regulator hose snapped. we jerry rigged it up but now when the car starts it shakes really bad. could this be because of the regulator hose?

    • ChiltonDIY says:

      Hi Dan.
      Yes, if the regulator hose connection is drawing in additional air then this will cause problems. I would replace the fuel pressure regulator. Make sure the spark plugs are properly gapped and the firing order is okay. Doublecheck your repair work and scan the vehicle for related diagnostic trouble codes (DTCs).
      If you find DTCs:
      • Your ChiltonDIY subscription includes a wealth of information about the DTCs the 1998 Monte Carlo might set, including possible causes for the DTC, diagnostic routines to address the issue, and clearing the codes once the Monte Carlo has been repaired. Refer to the Diagnostics section.
      • Look for the DTC in the technical service bulletins (TSBs) and recalls section of your ChiltonDIY to see whether General Motors has identified a common issue and prescribed a fix for it. With approximately 300 TSBs and recalls for the 1998 Monte Carlo, you can streamline your search by selecting the filter for “Symptoms” and choosing the symptom “DTC set.” You can also search by “Trouble Code.”

  13. maxx says:

    I have a 96 Toyota corolla and I just fixed my gas tank and now my fuel pump isn’t reading correctly and I worked just fine before I fixed it what could be the problem

    • ChiltonDIY says:

      Hi Maxx.
      Fuel gauge sending units are very fragile. It is very easy to damage the sending unit. Check all the connections. Check the operation of the sending unit.

  14. Brandon says:

    I have a 1988 c1500 would a bad fuel pump cause my truck to die at a stop? Its real sluggish when it drives and if i push the gas a hair more on the pedal it wants to stall but when i start to let off the gas pedal it wants to take off. I have changed the tsp sensor and the iac sensor new distributer plus and wires and still not running right.

    • ChiltonDIY says:

      Hi Brandon.
      Assuming you have good compression, check for vacuum leaks and inspect the EGR system. Check the base timing. Test the fuel pressure to see what it actually reads. What size engine do you have?

      • Brandon says:

        I have a 350 vortec with some preformance stuff so its a 383 stroker. Now im not sure how acurate this little gauge i on the back of the throttle body connected to the gas line but it reads a 9psi when im able to getthe truck started after about the 3rd time and im able to drive it after i start it because the truck is in a high idle but the rest of the day its hard to run since its not high idled any more. Ill look into the egr tomorrow with day light unless that rings a bell im not shure what the pressure needs to be

        • ChiltonDIY says:

          The fuel pressure specification for a 350 with throttle body injection is 12-15 psi. Brandon, does the truck have multiport injection? The specification for a multiport-injected system is 60-66 psi.
          Scan the vehicle for diagnostic trouble codes (DTCs) and look at the manifold absolute pressure (MAP) sensor. The engine control module (ECM) uses the MAP sensor to control fuel delivery and ignition timing.
          The MAP sensor reading is the opposite of what you would measure on a vacuum gauge. When manifold pressure is high, vacuum is low. The MAP sensor is also used to measure barometric pressure under certain conditions, which allows the ECM to automatically adjust for different altitudes. The ECM sends a 5 volt reference signal to the MAP sensor. As the manifold pressure changes, the electrical resistance of the sensor also changes. By monitoring the sensor output voltage, the ECM knows the manifold pressure. A higher pressure, low vacuum (high voltage) requires more fuel, while a lower pressure, higher vacuum (low voltage) requires less fuel.

  15. Mary says:

    Hello! I have a 2008 dodge avenger and in the past I had a problem with my fuel pump, the person who attempted to fix it snipped off a piece and indicated that it was burnt, so finally yesterday my car wouldn’t start, someone else checked it and stated that there is no fuel going into the engine at all, could the entire fuel pump need replacement or a piece of the fuel pump? Also what are the cause for a fuel pump to malfunction? Your answer would be greatly appreciated!

    • ChiltonDIY says:

      Hi Mary.
      Did he cut the strainer off? If the fuel pump is dead and without knowing what the previous person did, I think I would change the whole assembly.

      Causes of a malfunctioning fuel pump:
      1. Running low or out of fuel. When the fuel level is low, the pump must work much harder to produce the same pressure. This is because the reduced fuel weight no longer pushes fuel into the pump; instead the pump must draw the fuel in. A low fuel level also means there is less fuel to dissipate heat and lubricate the pump. The combination of an overworked pump and reduced cooling and lubrication will likely damage the fuel pump.
      2. Dirty fuel. Contaminants that enter the fuel tank are drawn through the fuel pump. The strainer on the pump is designed to remove larger (more than 70 microns) particles. Unfortunately, much smaller (30-40 microns) particles pass right through and do most of the damage.

      Note: A worn fuel pump draws additional amperage that often burns the connectors inside the pump. Burned connectors and harnesses on failed pumps are extremely common. Always check the connections carefully, before replacing the fuel pump. Failure to replace a burned connector will cause the replacement pump to fail very quickly.

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