Register now to get rid of these ads!

Fuel Gauge reading the fuel slosh

Discussion in 'The Hokey Ass Message Board' started by Crusty Nut, Oct 21, 2011.

  1. Crusty Nut
    Joined: Aug 3, 2005
    Posts: 1,834

    Crusty Nut

    Every aftermarket fuel gauge I've ever had, the needle wiggles all over from the sloshing fuel. OEM gauges don't do this. Is there some resister or regulator I can add to the wire to control this? It would seem like Radio Shack would offer some kind of electrical averager, but the only help they provide there is to take your money.
    Anyone have a fix for this, or am I the only one it bothers?
  2. D-man313
    Joined: Mar 17, 2011
    Posts: 1,162


    Mine does the same thing. When it didnt wiggle all over, the float was stuck, and i thought the sender was bad. Had to take it all apart and sand the float down a little, so it moves easier.
  3. 54fierro
    Joined: Jul 6, 2006
    Posts: 493

    from san diego

    Just recently i read somewhere that you can put a capacitor in line to absorb some of the spikes in resistance from the sender.

    My gauge does the same, hopefully some electrical wizard will chime in with some better info on this. Cesar
  4. Yep...Im curious about this too....

    Bump o rama


  5. KJSR
    Joined: Mar 7, 2008
    Posts: 2,485

    from Utah
    1. Utah HAMBers

    VW used one (most shops called it he vibrator) and it helped smooth out the reading. It was used in 68 and up bug for sure and I think the others as well.
  6. 39 All Ford
    Joined: Sep 15, 2008
    Posts: 1,531

    39 All Ford
    from Benton AR

    :D I like a little bit of gauge movement with fuel slosh, it lets me know if my tank is "empty" or "Really Empty"... (i.e. no slosh, no gas)

    I miss that on my late models....
  7. Tim
    Joined: Mar 2, 2001
    Posts: 13,129

    from KCMO

    i wonder how much of that has to do with different tanks having baffles in them and other not?
  8. Toolroomer
    Joined: Oct 22, 2010
    Posts: 36


    Would the constant voltage regulator from a Ford pickup in the mid '60's vintage do it. I have one on my coupe to step it down to the 6 volt guage. It seems to iron out the slosh on mine.

  9. 1950ChevySuburban
    Joined: Dec 20, 2006
    Posts: 6,188

    Member Emeritus
    from Tucson AZ

    Using the voltage regulator would require a gauge made for that.
    Tim- baffles DO make a difference.
    39All Ford - I'm with you, I like needle movement.

    Bottom line if you want less slosh movement, either use "balanced coil" gauges, or add baffles.
  10. railroad
    Joined: Feb 3, 2010
    Posts: 242


    I think the old Ford constant voltage regulators pulsed the voltage. It cuts off and on continuously. In a big tank it may not help, but the float needs to swing east and west not north and south.
  11. speedwise
    Joined: Aug 2, 2009
    Posts: 210


    I just check the gas level when I'm sitting still, it will stop moving. I bought those foam blocks from Speedway but found out they blocked the guage float.
  12. outlaw256
    Joined: Jun 26, 2008
    Posts: 2,023


    hell i just wish i had a fuel gauge!!i have never run out of gas in any of my cars while on the road, but i have run out of gas in the driveway in every one of luck aint gonna hold out much longer.
  13. Crusty Nut
    Joined: Aug 3, 2005
    Posts: 1,834

    Crusty Nut

    Okay, so the answer is there is no clear cut answer. I'm surprised there isn't some electrical do-dad to smooth out the surges.

    Oh, and my tank does has baffles.
  14. Crusty Nut
    Joined: Aug 3, 2005
    Posts: 1,834

    Crusty Nut

    one last bump looking for an answer.
  15. The_Monster
    Joined: Sep 8, 2003
    Posts: 1,754


    wow! No answer to the sloshy needle? Did anyone ever find a solution? I dont really mind a little movement, but when Im at half tank its flappin like metronome!!

    Also, my tank is empty when the needle reads half tank. Whats that all about??
  16. Here's the type that cured my fluctuating needle problem..Got it from ISS PRO gauges..they make all lengths for different depths,amperage ,etc...

    Attached Files:

  17. gas pumper
    Joined: Aug 13, 2007
    Posts: 2,956

    gas pumper

    I remember reading that OEM gauges that are steady have internal mechanical dampning. Drag on the needle/internals for us non-engineers.
  18. unkledaddy
    Joined: Jul 21, 2006
    Posts: 2,865


    Has anyone contacted a gauge manufacturer to discuss the problem?
  19. 1971BB427
    Joined: Mar 6, 2010
    Posts: 7,090

    from Oregon

    Baffles make a difference, as does location of the float, and direction. If the float is centrally located it will show less movement. If it's on one end or side of the tank it will be greatly affected by slosh. It's like a teeter-totter effect when the gas sloshes around, so something closer to center will not be affected as much.
  20. HotRodAV8
    Joined: Oct 7, 2002
    Posts: 88

    from Seattle Wa

    turbo26t nailed it! best sending unit made! THEY WORK LIKE YOU ALL WISH.even with foam. but you pay to play!
  21. Lobucrod
    Joined: Mar 22, 2006
    Posts: 4,122

    Alliance Vendor
    from Texas

    Having the float centered in the tank helps a lot. If it off to one side or in front or back it will fluctuate more.
  22. mashed
    Joined: Oct 15, 2011
    Posts: 1,474

    from 4077th

    VWs used a bi-metal fuel guage that was inherently dampened due to the time required to heat up. The "vibrator" was really a voltage regulator because of the sensitivity of the bi-metal design.

    The newer gauges are balance coil gauges, really a meter reader, and are quick to react. The only fix besides controlling the sloshing in the gas tank are the tubular fuel senders as posted above. Small holes are drilled in the outer tube so it takes several seconds for the fuel to flow in and out of the holes and for the float to respond.
  23. d2_willys
    Joined: Sep 8, 2007
    Posts: 4,188

    from Kansas

    If you supply the resistance of the sender unit then a couple of capacitors might help.

    Assuming you are using a balanced coil gauge type, the sender wire is connected to the junction of both coils, other end of one coil being connected to ground and other coil end to 12V. Object is to find the time constant (Resistance x Capacitance) that will slow down the movement.

    sender equals 0-90 ohms. Half of that is 45 ohms.

    So if you put a capacitor across the sender terminal to ground, and another across the sender to +12V you may be able to smooth out the gauge. The capacitors would probably be fairly large in value, but not voltage. I would think you could use 1000 mfd polarized types. You have to remember that the cap to ground would have + on sender terminal, where the other cap would have the + on 12V terminal.

    RS# <form action="/compare/index.jsp?categoryId=12648753" method="get" style="margin:0,0,0,0;display:inline;" name="compare"> </form> <form action="/compare/index.jsp" method="get" style="margin:0,0,0,0;display:inline;" name="compare0"> <input name="product_0" id="product_0" value="12460901" type="checkbox"> <label for="product_0" class="prodLoopSmallCopy_dark">[​IMG]</label> </form>

    Model: NTE NEV1000M25EF | Catalog #: 55047205


    Note: The marking on the cap for the - terminal.

    Wire it like this on gauge:

    12V term + 1000mfd - sender unit term. + 1000mfd - ground

Share This Page

Register now to get rid of these ads!


Copyright © 1995-2021 The Jalopy Journal: Steal our stuff, we'll kick your teeth in. Terms of Service. Privacy Policy.

Atomic Industry
Forum software by XenForo™ ©2010-2014 XenForo Ltd.