Announcement

Collapse
No announcement yet.

Fuel Sending Unit Repair

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

  • Fuel Sending Unit Repair

    Late in the season, the fuel sending unit went out on my '95 Prostar. Somebody suggested that it could be fixed. Instead of fixing it, I purchased a new one for $160.00 plus shipping. I left the old one on my work bench....until today.

    If you have this type of fuel sending unit, and it is inoperative, it is likely that the magnets have come dislodged from the foam float. It is a simple repair to get you back on the water.
    Name:  1ec3e90bf7f4036af7ead282fb72022a.jpg
Views: 1
Size:  77.7 KB

    There are three main components: The tube assembly, the circuit board, and the float. To disassemble the unit, remove the two screws at the bottom of the tube and remove the plastic cap. Then unscrew the two nuts at the top of the unit to allow the circuit board to slide out of the tube.

    The culprit in my unit were the two magnets that are supposed to be lodged in the foam float. They came out of the float and were resting on the tab at the bottom of the circuit board. I just used some 5 minute epoxy to connect the magnets back into the float. Then I used a fine file to smooth out the repair.
    Name:  25aa5195cccf0ec489b5c3b33531d2cd.jpg
Views: 1
Size:  32.8 KB

    I tested the unit by attaching an ohm meter to the circuit board, then moving the float. You can see in the next pictures that the reading on the guage changes as the float goes from the top (full) toward the bottom (empty).
    Name:  96e1e58347909cadeae3cf2e5d693221.jpg
Views: 1
Size:  59.8 KB
    Name:  44076e2418bdd2ccfafc588ef332f082.jpg
Views: 1
Size:  73.6 KB

    Reassembly is just the reverse of disassembly. I cleaned everything up with WD-40 first. Just be sure to insert the foam float into the tube before pushing the circuit board all the way to the top or the tab at the bottom of the circuit board will prevent you from inserting the float. Once assembled, I tested the unit again, this time by holding it right side up and upside down. This just verified that the unit is back in action. You can also connect it to the fuel guage wires and (with the key on) turn it up and down to view the fuel guage changing.
    Name:  d020f5add164e126eb8d83bafdce022c.jpg
Views: 1
Size:  58.1 KB


    Hope this helps somebody else in the future. I sure could have used that $160 some place else. This repair took only about 20 minutes and cost nothing.

  • #2
    Thanks, Skipper, that's the best write-up I've seen on this.

    I had to do the same to my boat 4 or 5 years ago; at that time, there were a few active threads on here about re-attaching the magnets. Haven't seen another mention since then.

    /frank
    1998 Maristar 200VRS

    Comment


    • #3
      When I first purchased my 1994 prostar 190 this summer I attempted fixing mine. I reattached a magnet that was loose without any improvements. I think my problem is that the foam float gets stuck.

      I may give mine another try next year after seeing that you were able to successfully fix yours.

      Comment


      • #4
        I found the same as Skipper - I had to do some shaving of the float to get it to move smoothly without sticking.
        1998 Maristar 200VRS

        Comment


        • #5
          There are two magnets. One goes on each end of the foam in the slot. If you have only one magnet, then it will not trigger the sensors in the circuit board. Using a fine file, I removed all of the epoxy covering the magnets on the foam and made the overall surface smoother.

          Comment


          • #6
            Originally posted by wtrskr View Post
            When I first purchased my 1994 prostar 190 this summer I attempted fixing mine. I reattached a magnet that was loose without any improvements. I think my problem is that the foam float gets stuck.

            I may give mine another try next year after seeing that you were able to successfully fix yours.
            The tube in my unit had some old fuel residue built up inside. I cleaned the tube and the circuit board with WD40. You can test the system by connecting to an ohm meter and moving the foam float across the back of the circuit board. The reading should change with the position of the float. If this works, then after you reassemble the unit turn it up and down and the foam float should fall freely. If it is cleaned up inside there should be nothing for it to hang up on in the tube. Also, be sure to file or sand down the front of the float where the magnets are closest to the circuit board. This will keep that surface smooth and will give the best interaction between the magnets and the circuit board.

            Comment


            • #7
              Excellent walkthrough. I added it to the FAQ.
              Previous: 1993 Prostar 205

              Red 1998 Closed Bow Ski Boat, Ford 351, 310 hp, Acme 4 blade, Perfect Pass SG.

              FAQ


              Tyler Ski Club


              To me, this forum is about love of inboard boats. It is about the sharing of information and, on a good day, some humor. It is not about post count, brand of boat, or any other superfluous labels that lend themselves to a false sense of superiority. Please, respect one another, try to pass on accurate information, and keep your eye on the ball.

              Comment


              • #8
                Originally posted by wtrskr View Post
                When I first purchased my 1994 prostar 190 this summer I attempted fixing mine. I reattached a magnet that was loose without any improvements. I think my problem is that the foam float gets stuck.

                I may give mine another try next year after seeing that you were able to successfully fix yours.
                I used to have a 92 ProSport 205 and when reformulated fuel came to our area in the mid 90's I had the same issue with the foam getting stuck. I think it swelled slightly with whatever they add to the gas. Anyway, I was able to sand it down slightly all the way around the edges of the float and did not have any further issues with the float for the remainder of the time I had the boat.

                Steve
                A positive attitude may not solve all your problems, but it will annoy enough people to make it worthwhile



                2004 Prostar 197 - Red on White

                350 TBI, Perfect Pass, Heater, Shower and a whole lot of fun!

                Comment


                • #9
                  I bought a new sending unit on skidim for $60. Seems a lot easier to replace than repair.

                  Either way thanks for the write up very informative.

                  Comment


                  • #10
                    only trick to the repair is aligning the magnets so the poles repel each other. can test by taping magnets in place and sliding along the powered circuit board while watching the fuel gauge.

                    Comment


                    • #11
                      Hi all

                      My Fuel gauge reading was playing around a bit last seat season , normally reading low.
                      With the track record of the sender units I have today taken it out with a view to find a magnet related fault , however the sender unit I have is a plastic tube and it does appear to have any retainer screws to enable me to get in side it .
                      By tipping up and down I can see the float move around but it does get stuck , which I am sure the the route cause of the problem .
                      There is a plastic plate on the bottom of the unit , which I would thin could be prised off and re glued .
                      Has any one come across the type of sender unit and if so how did you get inside.

                      thanks


                      Kevin

                      1993 prostar 190 285 hp inamr.

                      Comment


                      • #12
                        Update ,

                        Pried off the lower plate , sender setup up and design same as pictures, found both magnets stuck together in the middle of the float, cleaned the tube , glued the magnets back in their correct site (poles apart) , sanded down all the faces of the float , rebuilt it . glued back on the base cover.
                        Tested in and out of tank , now gauge works good as new .
                        Cost me 3 for the glue and a couple of hrs but saved me 150.00 for the part and I now know exactly how it works and it is done correctly (priceless).

                        Many thanks to all for this thread.


                        Kevin

                        Comment


                        • #13
                          Plus one more for this being the problem. Solved now. Thanks.

                          Just one question. My magnets were stuck together when they fell out. They are supposed to go into the slots on the top and bottom of the float and not in the middle? They need to be put in so they repel each other? I put them in the middle and the gauge was working, so I didn't think much of it until I came back and looked at the pictures again.
                          Last edited by mrprostar; 02-22-2011, 08:31 AM.
                          sigpic
                          1996 Prostar 205

                          Comment


                          • #14
                            I did this same repair on my 94 Prostar about 3 years ago...worked like charm. Excellent write up!
                            Guns don't kill people, I kill people

                            Comment


                            • #15
                              Going to work on my fuel sender this weekend and dug this thread out.

                              What epoxy shall I use for the magnets submerged in fuel?

                              Comment

                              Working...
                              X