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. Danielle says:

    Hi ChiltonDIY
    I have a V6. I had the spark plugs changed less than 3 months ago. After the vehicle warms up it runs just fine. But if I park the car & run an errand & come back sometimes it hesitates to start. I don’t know what codes are. I’m sorry but I am not familar with that. And I have 115,000 miles on the car.

    • ChiltonDIY says:

      You smell fuel, and it runs rough and hesitates after sitting, that sounds like a leaking injector or fuel pressure regulator. But the ignition coil, plug wires or spark plug could cause the same symptoms. If the plugs were changed recently, start there. You could have a bad connection at the coil or spark plug. Have your vehicle scanned for diagnostic trouble codes (DTCs).

      There are many hundreds of error codes (DTCs) that can occur; a DTC code indicates that some system of the car is experiencing a problem. When one of these errors occurs, it can turn on the “check engine” light on the dashboard. You will need a scan tool to retrieve DTCs. Chilton provides information about the DTCs the 2006 Pontiac G6 can generate with a subscription at http://www.ChiltonDIY.com.

      • Danielle Watson says:

        Where do you recommend I take it to have that diagnostic check for a low cost. I am on a tight budget right now, but I really need to find out whats wrong.

        • ChiltonDIY says:

          Danielle, here are some ideas:

          - Some auto parts stores scan for free. Try Autozone.
          - Basic scan tools just to read codes are $40.00 to $60.00. Innova has an OBD11 scan tool for around $60.00; it covers Domestic, Asian, European, Diesel, and Hybrid cars.
          - If you have an auto tech school in your area, they may work on the public’s cars and offer reduced rates. Check out their work and consider that the students are not professionals.

  2. Carrie says:

    I have a ’93 Ford Escort with 47,000 miles. Once when I was in the middle of traffic (in a turning lane stopped and ready to go left), my car completely shut off and would not turn over. I had to get it towed. When I got my inspection, we fixed a faulty idle air intake valve and reattached a disconnected hose. I think that solved the idling-then-stopping problem. Then, I got some body work done and the mechanic unplugged the battery. When he plugged it back in, I heard the buzzing you describe as my fuel pump working (apparently that happens when you reconnect the battery). That was 2 weeks ago.

    The sound actually startled me, as it has never done that before. Is it normal for me to never get that buzzing when I turn the car to ON without starting it? Just today I was heading up a hill, and suddenly I got a slight clanging under my driver’s side and the car seemed to not want to go. I’m wondering if it’s a sign of a faulty fuel pump (that’s the only time I felt like she wasn’t getting adequate power) or if it’s because I may have eased off the gas, thereby keeping the car in a low gear, then gunned it a bit and the low gear wasn’t ready to handle it. What do you think? Fuel pump problems? Car inspection was 2 months ago, and the fuel filter was changed then. I don’t know if they check fuel pumps during inspection though.

  3. Nicole says:

    Have a 97 acura RL car stopped on me at a Red light early in the morning. I started it right up and ran and errand parked car and it would not start again…I ran out of gas three days before. Is this a fuel pump, relay, or filter problem. Tow truck guy said this.

    • ChiltonDIY says:

      Hi Nicole. It may be a filter problem; do you run the fuel down close to E often? Have you changed the fuel filter? It should be changed at 60,000 miles. I like to change my filter every 30,000 miles.
      Import vehicles don’t seem to have as many problems with fuel pumps as domestics do.
      I would have the vehicle scanned to see if the PCM/ECM recorded a malfunction in the fuel system or ignition system.

  4. Elizabeth says:

    I have a 2000 Chevy Malibu that stalled while driving the other day. I assumed I ran out of gas (I was very low) but even after filling it up to half a tank it wouldn’t start. I did quite a bit of research and after resetting the anti-theft system the car will start, but it doesn’t stay on and putting the gas peddle to the floor does nothing. My dad suspects that running out of gas clogged the fuel filter, and not the fuel pump just because the car WILL start. Do you have any thoughts?

    • ChiltonDIY says:

      Hi Elizabeth.

      Verify it is a fuel problem:
      - Scan for diagnostic trouble codes
      - Check the fuel pressure. You can find the correct fuel pressure specification in your ChiltonDIY by following this path: PATH: Engine Mechanical > Specifications > Gasoline Engine Tune-Up Specifications.
      - Check/replace the external fuel filter. If you suspect the fuel sender/pump screen that means the fuel tank will need to be removed. I would replace the fuel pump at the same time.

      Caution: Observe all applicable safety precautions when working around fuel. Whenever servicing the fuel system, always work in a well-ventilated area. Do not allow fuel spray or vapors to come in contact with a spark or open flame. Keep a dry chemical fire extinguisher near the work area. Always keep fuel in a container specifically designed for fuel storage; also, always properly seal fuel containers to avoid the possibility of fire or explosion.

      There is a Technical Service Bulletin (TSB) that may be related. It is #00-06-04-044 Engine Hesitates, Stalls, Will Not Start (Replace Modular Fuel Sender Strainer). General Motors sends TSBs to its dealers when they identify an issue that affects a number of vehicles. You can access TSBs for your 2000 Chevy Malibu by subscribing at http://www.ChiltonDIY.com.

  5. jay says:

    I have a 2002 Dodge Neon and am experiencing similar issues. Sometimes it starts with some hesitation but recently, it would start with hesitation and then die, start up again and then die, repeat. And after several false starts, it wouldn’t start at all. Not the battery though — a/c, radio, etc come on, but the car won’t start. I can only get it to start if i pump the the gas a bit to around 1.5 RPMs. Took it in this week and was told the fuel pump needed to be replaced. $800 later, I have a new fuel pump, but after picking it up yesterday, the problem persists exactly as it was before. Now I’m at a loss. Any insight is appreciated. Thanks!

  6. Rickard says:

    I have a 1985 ford f150 with a 351 windsor 4 barrel holley carburetor. When I go to start it each morning it has a hard time starting but once it warms up it idles fine. When i go to pull out of my driveway or from a stop light the engine will start to wind up and then hit a dead spot where it stalls for a second and then revs back up and drives fine with plenty of power. Its only when you are starting from a stop. Its almost like it has a dead spot on the pedal. Once your past a certain rpm it has all the power in the world.

  7. Ashley says:

    Hi, I have a 1997 Chevy Suburban 2500 7.4L/454. I’ve owned it for a little over 2 years but I’ve only put right under 5000 miles on it. As soon as we fix one thing and start driving it another thing acts up. Well when we first bought it there were a couple of times it died out of nowhere. We thought it was related to the battery at the time because it had a loose connection. It sat for a year due to leaking intake manifold gaskets and a locked up smog pump pulley. When we had those fixed we found the culprit of why it would randomly die. Pin 30, the direct terminal that initially powers the fuel pump is becoming heated and melted. I’ve heard this could be due to a failing fuel pump that’s pulling too much current but have also read that a loose connection between the connector and the terminal can cause it to heat, as well as a wire short, or a faulty ground on pin 87a. I don’t know if the fuel pump has ever been replaced as I bought it through a dealer and didn’t receive any service records. The only time that it won’t start, or dies while running, are when the relay switch has become heated/melted enough. We keep a spare and all we have to do is pop in the new fuel relay switch and it fires right back up. It used to be that we could drive on one fuel relay for 2-3 months. We now have a lot less time and I don’t know if that’s due to the connection site becoming more and more damaged or does a failing fuel pump continue to increase the amount of current it pulls causing it to continuously heat up quicker and quicker? Also could a fuel pump be failing that long? We have had down periods with it but we’ve still put nearly 5000 miles on it since we bought it and it first died on us very soon after purchasing. I don’t know how long the problem was present for prior to purchasing but does it sound possible for it to fail for 5000 miles and not have given out yet? Also I put in the key and turned it forward and I do hear something turn on. One initial louder noise (on the driver side) and then also a soft continuous buzzing type noise (pretty much heard on the passenger side of the engine). I’m assuming the buzzing is the fuel pump but I’m not positive. The relay box is the opposite side on the driver side. I don’t experience any problems during acceleration or freeway driving. Also even if the connection site of the fuel relay switch (which is damaged (melted) and looser than the other terminal slots (metal pieces in the terminal slots are opened up more than the others)) could be part of the problem I don’t understand how it could cause the engine to die since I thought the oil pressure switch powers the fuel pump once the truck is running. I’ve read I should be able to remove the relay once the truck is running and it should continue to run. I tested this and it cause my vehicle to die. Any input is greatly appreciated.

    • ChiltonDIY says:

      Hi Ashley. I would install a new relay connector and relay, a poor connection can cause resistance and overheating at the relay.

      Check the fuel pump operation. Check the fuel pressure. You can find the correct specification in your ChiltonDIY. Inspect the grounds and wiring. Perform a voltage drop test on the fuel pump. It may be a bad connection with the fuel pump harness. The procedure and specifications for the voltage drop test are available when you subscribe to the information for your 1997 Chevrolet Suburban 2500 at http://www.ChiltonDIY.com. (Ashley you can use the navigation outline to follow this path: Chassis Electrical > Understanding & Troubleshooting Electrical Systems > Voltage > Voltage Drop)

      There are some Technical Service Bulletins (TSBs) for your 1997 Chevy Suburban 2500 that may be related. TSBs are information the vehicle manufacturer sends to their dealers. When there are issues that occur repeatedly a vehicle manufacturer might release a TSB to help dealer technicians make repairs more cost-effectively. TSBs are available with your subscription for your Suburban at http://www.ChiltonDIY.com.

      TSBs that may help with your issue are:

      #77-63-06A: No Start, Stall …
      #04-06-04-088C: Replacement of Connector …
      #02-06-03-012: Proper Diagnostic Procedures …

      • Ashley says:

        Thank you so much for all of the information!! You’re awesome! I purchased a subscription but the TSBs that you listed, specifically the one on replacing the connector, is not showing up in my TSB list?

  8. Kristina says:

    I’m having similar problems with slight differences.
    I drive a ’00 Ford Focus. About 3 weeks ago there was a flood and my car was a little below seat level in water for a few minutes.
    After the water went away she ran fine with a little sputtering.
    My friend works on cars and put Lucas in the tank to get the water out. Then for a few days it would sputter then die on me. So we tried several things: replaced the ignition coil. Seemed to work for a few miles, then repeat what it used to do. Then tried replacing the fuel filter. Again, it worked fine for a few miles then would stall out and die. Directly after the fuel filter replacement, I would drive and would start to show signs that it was gonna die and the only way to keep it from dying is to give it gas, but then at some points it seemed the more gas I’d give it, the lower the RPMs got and then eventually die.
    The next day I drove it to run errands. Ran fine til about 3/4 of the way there when it died and refused to turn over. Finally after about 2 hours of sitting there, it starts and I make it home. My car guy says he thinks it just a lot of water in the tank. My other friend that works on cars in a different state swears it’s the fuel pump. So my friends gonna replace it tomorrow but if that doesn’t work, do you have suggestions as to what else it could be?
    Oh yeah and before the fuel filter replacement the guys at Valvoline checked it for codes. The first time it read out 2 codes. One being a misfire in one of the ignition coils and one they said wasn’t related to what my problem was. I accidentally left my lights on over night which drained the battery and after the battery was fully charged again, it wasn’t reading any codes. (We replaced the ignition coil so that fixed that misfire code)
    Sorry for the long post.

    • ChiltonDIY says:

      Hi Kristina.

      When your car has been submerged in water, there can be problems immediately and problems can crop up in the future. Things can start to corrode. If it was salt water, it can create havoc.

      Contact your insurance company. They should be able to help with flood repair. For example, car manufacturers specify solutions that can be sprayed on wires and connectors to help disperse the moisture and protect against rust and corrosion. A technician can apply additional dielectric grease where needed, and perhaps take other measures to protect your car.

      Regarding the stalling condition:

      1. Make sure there’s no water in the tank. If there’s water in the tank, your engine can’t burn water. When you take the tank down you can test for volume of water and pressure.
      2. Check all electrical connections. In addition, with all that moisture, if the computer got damp it could cause the problems your vehicle is experiencing too.

  9. Mary Jane says:

    Hi! I have a 96 Ford Explorer Sport. Have not started the car in 4 years. I finally did last week, got A brand new battery, reset the alarm system, got some fuel cleaner, and tried to start the car. It cranks but won’t start so I got a Starter Fluid. It started but would cut out right away. What could it be?

    • ChiltonDIY says:

      Hi Mary Jane. Take the gas out of the tank. After 4 years it will turn to varnish. If you smell the cap it won’t smell like gas, it will smell like a lacquer. If the gas is old it won’t burn.

      If they pull the tank they can check the fuel pump while it is down.

      The fact that it started when you sprayed it means it’s getting a spark but not getting fuel.

  10. Aubrey Copeland says:

    How you doing? I have an 95 9c1 caprice, I replaced my fuel pump because it had went out. Just purchased the fuel pump only and now my gauge isn’t working I double checked all connections. Do you think I need a new sending unit or what pls help!! Really need that gas gauge lol

    • ChiltonDIY says:

      Hi Aubrey. When the fuel pump was replaced, it is possible the sending unit was damaged. The sending unit is very sensitive and can be damaged if bumped. Check the sending unit. Check all the connections. Make sure the fuel gauge has the capability of working.
      In addition, General Motors released a Technical Service Bulletin (TSB) which may be related to the concern. If you read the previous posts, you saw that a TSB can give information about how to address a recurring issue. Rule out TSB #67-65-19 as a potential cause of the inaccurate fuel gauge.
      You can obtain the Recalls and TSBs for your vehicle, along with service and repair information at http://www.ChiltonDIY.com.

  11. joe says:

    hey, ive got a 76 chevy c10 with a 350 bored. 30 with a mild cam and a holly 650 carb. she was sitting for a while got her running ran fine for a day or two, took her to get an oil change and she was bogging real bad leaving a stop this started after the 2 days of running perfect. then driving hone she kept stalling then would be had to start. towed her home and after sitting for about a week she ran fine drove for an hour with no problem now shes stalking again with the hard start. if i sit n let her cool down i can get about a mile before she stalls again, any ideas? also dunno if it makea a difference but there are no cats just stright pipes.

    • ChiltonDIY says:

      Hi Joe.

      You’ll want to determine whether it is a problem with spark or fuel.
      Check the carb. Is it dripping or running rich? Maybe the needle valve is sticking or the power valve could be bad.
      If you have points, check the points and condenser and make sure they are not burnt and closed up. Check the dwell and timing.

  12. Brianna Jimenez says:

    Hi, I have a 2002 Chevy Malibu, and it sometimes has trouble starting. I spray starting fluid and it turns on but recently its been wanting to turn on but the car starts to shake then cuts off. After that we have to wait for like a hour or so for it to start again. We’ve replaced the spark plugs and can hear the fuel pump coming on. I’ve used seafoam to try and clean out any clogs, and still has same issues. What else could it be?

    • ChiltonDIY says:

      Hi Brianna.

      Check the fuel pressure
      Scan for codes
      Check to see if you have a good hot spark on all cylinders
      Check the compression

  13. mia says:

    Hey, I have a 2002 silverado truck v6, as I was driving hme I heard a noise nd it sounded like a struggle. ( I had gas but I aspiring drive a lot on close to empty) I made it hme but it sounded funny and it seem to make a sputtered noise as I press the gas and if I increase on the gas it seems like its going to die. It did a few times but started up again. When I reverse it fire out too. Is it my fuel pump or vaccume leakage fr what I was told. Jus wanna a accurate answer thanks

    • ChiltonDIY says:

      Hi Mia. Running on empty can damage your fuel pump and filter and cause your engine to run poorly – here’s why:

      Gas is not completely clean. If you run your truck on E a lot you are sucking up debris/ silt on the sock which filters the gas in your truck’s fuel pump. The silt clogs up the sock and the fuel can’t get through.
      When you run the gas all the way down to E and you get a little moisture in the tank, say for example by pumping gas in the rain, then you may be trying to run the engine on water. The engine won’t run on water.
      In addition, the fuel pump is submerged in gas which helps keep it cool. When there’s not much gas the fuel pump doesn’t keep cool and experiences more wear.

      Without seeing the vehicle, it sounds like you may need a filter and may have a failing fuel pump.

      Check the fuel pressure.

      • mia says:

        Thank you for your help. The problem was not my fuel pump, I was told if it was it wouldn’t start. my friend did a code scan and it was reading a misfire which was the noise I heard a couple times, so it ended up needing tune up. And it runs good and it dosent make that funny noise when I start it up. Apparently my wires nd rotor was irked or something.

  14. patrick says:

    i have a 2000 Chevy venture it will start and run rough then if you turn it off it wont start again if its let sit for a couple hours it will start again and it will get me to where I’m going but then i haft to let it sit again now when i start it it idles but if you step on the gas it sputters and when your going down the road it doesn’t want to get up to speed i have replaced the ERG and replaced the fuel pressure regulator could it be the fuel pump please help me I’m at my wits end

  15. patrick says:

    sorry also when it stops running or when it goes out the exhaust pops and there’s what smells like gas or exhaust

    • ChiltonDIY says:

      Hi Patrick.

      - Scan your Chevy Venture to see if you have any misfire codes.
      - Have you checked the fuel pressure? Check your ChiltonDIY subscription for the correct fuel pressure specification (under Engine Mechanical Specifications).
      - Was the fuel filter replaced?
      - A clogged exhaust system (catalytic converter) can also cause your problem.

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