How a Fuel Pump Works

  • Published on Jun 19, 2017
  • Here's what's inside the fuel pump and how it works on your car.
    The fuel pump, or fuel sender unit, is responsible for sending pressurized fuel to the fuel rail on the engine. It is normally situated inside the gas tank, cooled by surrounding fuel.
    The fuel pump assembly consists of an electric DC motor with a paddle, a pickup screen, float, tank level sensing unit, filter, pressure regulator as well as the empty level sensor.
    The DC motor drawings fuel through a turning paddle in through the housing of the motor, past the rotors and brushes out the top.
    Fuel then saturates the filter, where it can then make its way up the top to the fuel line leading to the engine. Excess pressure built up in the filter is bled off through a pressure regulator valve at the bottom of the assembly, where the fuel is returned to the tank.
    The tank float attaches to an arm that attaches to a metal head. The head moves in a semi circular pattern against a circuit board with printed resistors. The measured resistance values are relayed back to the instrument cluster to determine fuel amount.
    The empty level sensor is a device that looks like a resistor. When submerged in fluid, it reads 2K ohms. When dry, it reads an open circuit and turns the light on the dashboard warning of low fuel in the tank.
    Assembly of these components are held together by plastic pieces which are clipped together. Often these require disassembly when replacing defective pump units, as only the motor needs to be replaced.
    The fuel pump in this video was removed from a 2001 Toyota Corolla.
    Link to Etsy shop where you can purchase speedkar99's brother's socks, t-shirts or hoodies:
    Check out the speedkar99 Facebook page:
    Check out the speedkar99 Linkedin page:
    Follow speedkar9 on Instagram for behind the scenes coverage:
    Subscribe for more videos just like this:
  • Autos & VehiclesAutos & Vehicles

Comments • 649

  • Krishna Kanth
    Krishna Kanth 2 days ago +1

    Very good explanation of electric fuel pump
    Crisp and concise !

  • Lifenod
    Lifenod 10 days ago +1

    Nice toothbrush teacher

  • Paul Varathan
    Paul Varathan 10 days ago +1

    Very good tutorial. All we do is sit and drive our vehicles. Without the fuel pump we are going no where.

    • Paul Varathan
      Paul Varathan 9 days ago

      @speedkar99 Yes...thats right..

    • speedkar99
      speedkar99  9 days ago

      Agreed. Just as vital as...your tires or engine.

  • Paul Vickers
    Paul Vickers 14 days ago +1

    I bought a 2000 f150 recently.The owner put a new fuel pump in.It ran good for about 1,500 mi then it began hesitating between 30&40 mi.per hr.
    I figured out that it will run good at full tank until I use about 6 gal.Then it starts to malfunction.When it begins to malfunction it might run good for 2-3 mi.then it starts to hesitate at the speed mentioned.
    Any answers or advise?

  • Moon shiner
    Moon shiner 18 days ago +1

    That was brilliant !

  • dydx solutions
    dydx solutions 19 days ago +1

    What car was it ?

  • dydx solutions
    dydx solutions 19 days ago +1


    JASON BARRERA 21 day ago +1

    Does the fuel pump cause my car to rattle when I start it in the mornings ? When I drive it for the first 5 min, it’ll rattle but then it stops for the rest of the day

  • nebojsa stojiljkovic
    nebojsa stojiljkovic 29 days ago +1

    Tesla sistem !!!

  • Caleb S
    Caleb S Month ago +1

    My brother's sock.

  • Felipe Catellani
    Felipe Catellani Month ago +1

    Can it be a 2 way pump?

    YACINE YACINE06 2 months ago +1

    Excellent video ... Are electricity pumps only exist in the injection system ??

      YACINE YACINE06 2 months ago

      @speedkar99 👍

    • speedkar99
      speedkar99  2 months ago +1

      Older vehicles have mechanical pumps drivien off the camshaft

    SURAJ DHARMAVIRA 2 months ago +1

    Perfect presentation. Everything covered. Thanks

    ZORSHRINER 2 months ago +1

    So much technology and details in a fuel pump, it is a magnificent complex of ingenuity. The more he cuts to find details, the more I appreciate engineering.

    • speedkar99
      speedkar99  2 months ago

      I agree! I have a totally different perspective on cars, engineering and mass manufacturing now.

  • Dasari Venkata Sreekanth
    Dasari Venkata Sreekanth 2 months ago +1

    Great content good explanation sir do more

  • kolbpilot
    kolbpilot 2 months ago +1

    Good stuff.

  • chanti yalla
    chanti yalla 2 months ago +1

    Excellent video

  • Abd Aziz Abd Hamid
    Abd Aziz Abd Hamid 2 months ago +1

    Is open circuit on sensor that will light up low level warning? How is the circuit?

    • speedkar99
      speedkar99  2 months ago

      That's built into the cluster

  • Khaled Manse
    Khaled Manse 2 months ago +1

    thanks man this was a clear explanation greets from egypt go on

    • speedkar99
      speedkar99  2 months ago +1

      You are welcome from Canada!

  • Best Videos
    Best Videos 2 months ago +1

    What a great video

  • LotWizzard
    LotWizzard 3 months ago +1

    nice breakdown

  • Maldo Han
    Maldo Han 3 months ago +1

    It's called an impeller

  • Prasad Chinthaka
    Prasad Chinthaka 3 months ago +1

    And can i know how to find the common fuel pump + and - wire by colour coding. bcoz i need to put a reply. So please kindly explain

    • speedkar99
      speedkar99  3 months ago

      Wiring diagram
      Trace wires to motor
      The two thicker wires are typically the power on the harness

  • Prasad Chinthaka
    Prasad Chinthaka 3 months ago +1

    thank you sir, very valuable for me

    PHENOMENAL VLOGS 3 months ago +1

    My sending unit looks similar to mine. 2003 4Runner. My problem is it primes and I hear it after replacing it. But for some reason it must not be getting gas to the engine

      PHENOMENAL VLOGS 3 months ago

      @speedkar99 Don't know, but I'm at a loss with it

    • speedkar99
      speedkar99  3 months ago

      Maybe you have a blockage in the line or regulator

  • Chemical Spore
    Chemical Spore 3 months ago +1

    "Today on this old sock"

  • Jack Kane
    Jack Kane 3 months ago

    Great video .

  • selador11
    selador11 3 months ago +1

    Good video. Should have ended the vid with a shot of your brother's feet, walking around in a soggy sock...

    • selador11
      selador11 3 months ago

      A close-in shot would be best. No need to see anything more than the feet. And maybe three really soggy steps.

    • selador11
      selador11 3 months ago

      No need for fire. Just soaking a sock in water, and having him walk by with just the one soggy sock, would do the trick. =0)

    • speedkar99
      speedkar99  3 months ago

      Haha good one
      Then the sock catches fire from the fuel

  • Tony Crespo
    Tony Crespo 4 months ago +1

    Great video!

  • Spare Motor Parts Bd
    Spare Motor Parts Bd 4 months ago +1

    Realy Interesting video

  • Scott Weatherman
    Scott Weatherman 4 months ago +1

    Well made. Thanks

  • speedkar99
    speedkar99  4 months ago

    Replacement fuel pump motors can be found here:
    A basic metric socket set is all you need to access it:
    If you are having issues with fuel pressure, check it using this tool from OTC:

  • Mahmoud
    Mahmoud 4 months ago +2

    Expert video! great content, thank you very much bro

    keep going

  • Anil Kumar Sharma
    Anil Kumar Sharma 4 months ago +1

    do you know the fuel inject inside the internal combustion engine of ace hydra crane, is same nozzle pour more diesel if we use crane at it's full swing capacity
    how much fuel inject per second in 12xw ace crane engine and produced how much energy so we know how much fuel consuming every hours if 2200 rpm and 48 bhp give by engine

  • G Lasser
    G Lasser 4 months ago +1

    Thanks for this perfect AtoZ system presentation. 👍🏻
    I thought my pressure regulator was shot but now I see it may really be the filter media that is all plugged up 😂
    These simple designs are called RETURN-LESS fuel delivery systems.
    The pressure regulator stays cooler in the tank than in the engine bay.
    Zero electronic control involved, just a simple diaphragm & opposing spring.
    Very resilient German design when it's made for Japanese cars.

    • speedkar99
      speedkar99  4 months ago +1

      Returnless is way better than dealing with two fuel lines

  • James Schiltz
    James Schiltz 4 months ago +1


  • Ralph Nabozny
    Ralph Nabozny 4 months ago +1

    every kid 10 yrs old and over should watch all yourvideos

  • Ralph Nabozny
    Ralph Nabozny 4 months ago +1

    hows your wifes tooth brush doing?

    • speedkar99
      speedkar99  4 months ago

      I got my eyes on soon as she's not'll see it in the next video 😲

  • eleven0xi
    eleven0xi 4 months ago +1


  • logical canuck
    logical canuck 5 months ago +1

    I chastised a popular TVclipr not so much for using shop air to do EVAP smoke testing but for not disconnecting battery and other disregard for the hazard created while doing it.
    Normally, there are hydrocarbons in tank and no oxygen present so an energized fuel pump isn't a concern.
    BUT, when shop air displaces the hydrocarbons then all bets are off!
    If one choses to use shop air to do EVAP smoke testing, at the very least DISCONNECT the battery!

  • dasun athuraliya
    dasun athuraliya 5 months ago +1

    හොදම පැහැදිලි කිරිමක්, අනිවාරෙන් ඔයාගේ video නරඹනවා, superb, grate work, translate you my word, it sinhala

  • Ali Haleem
    Ali Haleem 5 months ago +1

    Great video thank you so much

  • .
    . 5 months ago

    I took my truck tonthe mechanic, gas pump was not working properly and i got a new pump, it took him 3 days to have it ready for me and as soon as I started driving i went to the gas station fill up my tank and i did not read how much gas i had on my tank, told the mechanic and he said to leave it again he said my truck was fine but my gas reader still does not show when I fill up my tank then he said if I bring it again he will charge me again :(

    • .
      . 5 months ago

      I have a friend he says he can fix it so i will try and do it by myself and my friends help , with your video now I feel i can do it :)

  • Abdelmounim Hamdaoui
    Abdelmounim Hamdaoui 5 months ago +1

    Nice, quick and very informative.
    I like the way that you open everything and explain and do all this quickly.

    • G Lasser
      G Lasser 4 months ago

      @speedkar99 the good thing is you consitently do that with a LINEAR LOGIC that is easy to understand, your trade mark !

    • speedkar99
      speedkar99  5 months ago

      Thanks. Short and to the point is my style

  • Joe _
    Joe _ 5 months ago +1

    Damn this dude knows his shit

  • khurramali
    khurramali 5 months ago +1

    great videos

  • Natalie Tanner
    Natalie Tanner 5 months ago +1

    RIP fuel pump and every single additional part associated to the fuel pump.

  • Damian Poma
    Damian Poma 5 months ago

    I’m gonna give you a like, but first, let’s cut it open to see what’s inside.

  • Beware Be Carefull
    Beware Be Carefull 5 months ago +2

    My car is suddenly stopping after running for 10 to 12 kms and engine is getting heat do u think there is a fuel pump issue in it..

    • Cucu Lob
      Cucu Lob 4 months ago

      Nice one bro

    • whitehorse1959
      whitehorse1959 5 months ago +1

      Very unlikely to be the fuel pump. Symptoms are different - like car won't drive fast, only slow if fuel not pumping properly. Check your coolant and your oil levels. Make sure the engine is not overheating and seizing.

  • Preston Thugman
    Preston Thugman 5 months ago +1

    Wow. !

  • Swizzle Dwezzl
    Swizzle Dwezzl 5 months ago +1

    I can’t believe that there’s 203 stupid assholes that dislike this fully professional explanatory video, it can’t be more educational than this, This Guy took the time to do a fully compressed demonstration in how this system works, and yet there’s “ Envious assholes “ disliking the video, I’m 100% sure that none of those morons knows how to even put some gas on a car !!. This is an excellent video that most of car enthusiasts must watch just for a basic knowledge. 👍👍👍👍👍👍

    • speedkar99
      speedkar99  5 months ago +1

      Thanks for the kind feedback. I'm sure those dislikes are from my brother for using his things

  • Robert Mkony
    Robert Mkony 5 months ago +1

    I won't leave without subscribing to your channel.

  • Venture Electronics
    Venture Electronics 5 months ago +1

    Don"t forget to give your brother his sock and toothbrush.

  • sajsed2
    sajsed2 5 months ago +23

    Great content as usual, your brother needs to keep an eye on his clothes hahahhaha

  • Geva Soraski
    Geva Soraski 5 months ago +2


  • Chris Chery
    Chris Chery 5 months ago +2

    I can thank you so much and woooooow you are a massive professional experience mechanic I've ever seen in you tube again and woooooow and than keep up the good work

  • MunMun Miao
    MunMun Miao 5 months ago +1


  • Yuck Foutube
    Yuck Foutube 6 months ago +1

    There's just something weird about having a motor submerged in fuel.

  • Sumit Chauhan
    Sumit Chauhan 6 months ago

    This video is the real example for those who make this type of videos. Really excellent video

  • Mudhut Productions
    Mudhut Productions 6 months ago +1

    Great vid!