Announcement

Collapse
No announcement yet.

OFF TOPIC How do the low pressure gasoline fuel pumps work

Collapse
X
 
  • Filter
  • Time
  • Show
Clear All
new posts

  • OFF TOPIC How do the low pressure gasoline fuel pumps work

    I have large lawn mowers and other outdoor 12volt gasoline equipment. I allways install aftermarket fuel pumps. No mater how long the mower sits without useing,if you turn the pump on for a minute it fills the carb bowl and starts instantly .They are trouble free. I took an old one apart to see how it works. It has a coil and an oscillating piston. I didnt see any points to make the piston go back and forth. Does anyone know how they work? Thanks in advance . Edwin Dirnbeck

  • #2
    Hurry up people, now I have read the post, I want to know as well.

    Comment


    • #3
      The older pump designs often used points in order to oscillate the piston. The points were often housed in a sealed chamber filled with an inert gas like argon in order to prolong point life.
      Newer pumps styles like the Facet pump below now use a solid state electronics circuit to replace the points.

      Click image for larger version

Name:	Facet.jpg
Views:	255
Size:	27.4 KB
ID:	1945716

      Home, down in the valley behind the Red Angus
      Bad Decisions Make Good Stories​

      Location: British Columbia

      Comment


      • #4
        Facet pumps are still made in New York state.
        Rochester I think.
        I keep one around the shop with some hose and
        battery clips, just so I don't have to taste gas anymore
        should the need arise.

        -Doozer
        DZER

        Comment


        • #5
          Doozer, remember though that these types of pumps work much better at pushing fuel than lifting it if the need should occur to suck some gasoline out of a car's fuel fill pipe.
          You may still need to lift by other means as they create no vacuum so they will absolutely not work for that type of service. They work best when gravity fed.
          Keep these breath mints handy.
          Home, down in the valley behind the Red Angus
          Bad Decisions Make Good Stories​

          Location: British Columbia

          Comment


          • #6
            Originally posted by Willy View Post
            Doozer, remember though that these types of pumps work much better at pushing fuel than lifting it if the need should occur to suck some gasoline out of a car's fuel fill pipe.
            You may still need to lift by other means as they create no vacuum so they will absolutely not work for that type of service. They work best when gravity fed.
            Keep these breath mints handy.
            I have a pump that is mounted about 2 inches ABOVE the TOP of gas tank. I ran out of gas put 2 gallons in. The gas was 8 inches below pump. I let the pump buzz for about a minute and the mower started right up..Maybe their was enough gas id the lines to prime the pump. Edwin Dirnbeck

            Comment


            • #7
              Originally posted by Willy View Post
              The older pump designs often used points in order to oscillate the piston. The points were often housed in a sealed chamber filled with an inert gas like argon in order to prolong point life.
              Newer pumps styles like the Facet pump below now use a solid state electronics circuit to replace the points.

              Click image for larger version

Name:	Facet.jpg
Views:	255
Size:	27.4 KB
ID:	1945716
              Willey, thanks for the reply. The pump that I tore apart must have had a hidden circuit board. Edwin Dirnbeck

              Comment


              • #8
                Now, I understand, the simple electronics produce an AC low frequency in the coil and the piston oscillates sympathetically. The pressure would be very low, which is just what is required.

                Comment


                • #9
                  Originally posted by old mart View Post
                  Now, I understand, the simple electronics produce an AC low frequency in the coil and the piston oscillates sympathetically. The pressure would be very low, which is just what is required.
                  To be honest the last time I had one apart I did not investigate the circuit to see if it was a low freq. AC or pulsating DC that was used to drive the coil in order to oscillate the pump's piston. I assumed it was pulsating DC but not being EE I could be wrong.
                  Home, down in the valley behind the Red Angus
                  Bad Decisions Make Good Stories​

                  Location: British Columbia

                  Comment


                  • #10
                    Low frequency AC or pulsating DC? Not much difference, really.



                    Originally posted by Willy View Post

                    To be honest the last time I had one apart I did not investigate the circuit to see if it was a low freq. AC or pulsating DC that was used to drive the coil in order to oscillate the pump's piston. I assumed it was pulsating DC but not being EE I could be wrong.
                    Paul A.
                    SE Texas

                    And if you look REAL close at an analog signal,
                    You will find that it has discrete steps.

                    Comment


                    • #11
                      Originally posted by old mart View Post
                      Now, I understand, the simple electronics produce an AC low frequency in the coil and the piston oscillates sympathetically. The pressure would be very low, which is just what is required.
                      If I recall, the older model Subaru cars with carburetors had a fuel pump similar to this, it's quite useful for transferring fluids of all kinds on the cheap.
                      25 miles north of Buffalo NY, USA

                      Comment


                      • #12
                        Originally posted by Paul Alciatore View Post
                        Low frequency AC or pulsating DC? Not much difference, really.




                        Functionally very little difference I agree.But I had assumed that being a DC powered circuit that switching the DC to AC would have been a less efficient way to accomplish the same end result. than by simply pulsating the existing DC. ????
                        Thoughts.

                        Being a lo-tech automotive application IC or circuit cost would likely be the deciding factor I suppose.
                        Home, down in the valley behind the Red Angus
                        Bad Decisions Make Good Stories​

                        Location: British Columbia

                        Comment


                        • #13
                          The pulsating DC would be a better way as long as it was the correct polarity to work against the spring. AC might not require the spring.

                          Comment


                          • #14
                            A magnet will have an attraction for iron, regardless of the DC polarity or if it is powered by AC.
                            Elementary school science here folks.

                            -D

                            DZER

                            Comment


                            • #15
                              Originally posted by Doozer View Post
                              A magnet will have an attraction for iron, regardless of the DC polarity or if it is powered by AC.
                              Elementary school science here folks.

                              -D
                              Hot tip Sherlock.
                              But which one has the greatest overall electrical and cost efficiency?
                              Home, down in the valley behind the Red Angus
                              Bad Decisions Make Good Stories​

                              Location: British Columbia

                              Comment

                              Working...
                              X