help with fuel gauge

Discussion in 'Sparky's corner' started by magic marouke, Jan 11, 2018.

  1. magic marouke

    magic marouke Well-Known Member

    yes i know its a common problem and ive searched on here for a solution . also hope this is the right place for this thread .
    after about a week and 80 miles of owning the car i noticed the fuel gauge was still on nearly full (not all the way over like when one normally goes out). i filled up with 18 gallons of gas and is twitched a bit but basically stayed put . the ground wire looks ok coming from the tank . also took the tan wire from inside the trunk and grounded it with ignition on . instead of going to empty like a working gauge would it went from nearly full
    to past full .
    am i missing anything obvious before i let the tank down and check the wire on top of the sender and if bad replacing it
    thanks guys

  2. Brad W

    Brad W Miles from nowhere...

    I had kinda the same thing but crawling under the car and cleaning where the ground wire was attached to the floor pan, then spraying contact cleaner on the connector on the tan wire where it conects to the sending wire(mine was by the trunk latch) and did the trick. I also jiggled the connector after I sprayed the cleaned to work it in.

    There are other guys here that have more knowledge then me past that.
  3. magic marouke

    magic marouke Well-Known Member

    thanks Brad . ive cleaned around where the ground wire is and it looks ok . of course it may not be so good at the sender end and wont know until i drop the tank . may buy a new sender as ill have the tank down anyway
  4. knucklebusted

    knucklebusted Well-Known Member

    If you disconnect it completely, where does it go? Grounded should go one way, open circuit should go full the other way. I've been tempted to wire in a small resistor to get mine to read a little more accurately. My GS gauge goes past full and takes about 50-75 (12-13MPG) miles to drop below the full line.
  5. Brad W

    Brad W Miles from nowhere...

    Mine does the exact same thing. I have to be carefull because when at 1/4 tank I've got 3 gallons left!
  6. bullheimer

    bullheimer Active Member

    i'm in the same boat. will try the above as well as running a new wire from sender to gauge and see what happens. i'm down to about 10 minutes to remove my inst. cluster these days. just has to not be freezing for me to be motivated.
  7. magic marouke

    magic marouke Well-Known Member

    I bought a new sender for $38 . Figured if I’m dropping the tank to check connections in the sender it won’t hurt to get one if I need one . Don’t wanna take the tank down again
  8. buick64203

    buick64203 Buick Hunter Staff Member

  9. magic marouke

    magic marouke Well-Known Member

    thanks everyone I now have a working fuel gauge . really hate it when they don't work . tested the new one on the gauge first and worked fine .
    dropped the tank and fitted new sender . original one looked completely different like a big cylinder deal . the swearing started when id bolted the tank back up
    and hooked all the lines up . I forgot to attach the power wire to the sender DOH !!!! anyway it all worked out so must have been the original faulty sender .

    thanks again
  10. Electra Bob

    Electra Bob Well-Known Member

    Hey MM - any tips and insights on doing the tank drop and sender swap greatly appreciated.

    I've had a replacement sender sitting on a shelf for almost as long as I've had the car now and I think it's about time I got around to fitting it!

    Did you have to completely drain and drop the tank?

    Also - what's with all those pipes sprouting out the tank??? I lost count!

    magic marouke likes this.
  11. magic marouke

    magic marouke Well-Known Member

    its actually fairly easy . obviously the less fuel in the tank the better . i didnt want to be stuck running out of gas so drained the gas out once id dropped the tank . i used a thick piece of board about 3 feet square to lower the tank . make sure you can undo the straps and lower the tank without the straps getting trapped between the board and the tank. once the tank was down i pumped about 10 gallons out using one of those hand pumps . left a couple gallons in there , no way i would have lifted the tank back up on my own with all that gas in .
    make sure your new sender works before you even get under the car . just connect it to the tan wire going in to the trunk . ground it and with ignition on raise the float and you should see the gauge move hopefully .
    theres a few vapor lines youll need to take off , just make sure you get them in the right order when connecting back up . if you can replace any vapor and gas lines that look dodgy while you have the tank down .
    take care removing the old sender as not to get dirt in the tank . clean around the opening also making sure dirt doesnt drop in . make sure you have the ground wire routed down the groove at the top of the tank so you dont pinch it between the tank and car body , just tape it in place , same for the power wire from the sender to the rear of car .
    if you have a buddy around grab him to help lift the tank back up . i did it on my own but it can be done .
    connect back the two gas feed and return lines to sender and all the vapor lines . you cant really get them wrong .
    start the car and enjoy your fuel gauge . mine took a little while to register once the gas was back in . also braking and cornering affects it a lot but settles back down once cruising .
    good luck dude and if you have any more questions just ask .


    Last edited: Mar 6, 2018
    Electra Bob likes this.
  12. Electra Bob

    Electra Bob Well-Known Member

    Great! Thanks for the info. Looks like this job is moving up the list. Well - maybe when it gets above freezing and all the snow is gone. I think I'd rather do this outside than in a cramped garage.

  13. magic marouke

    magic marouke Well-Known Member

    think I had it all done in a couple of hours including taking the bloody tank down again after forgetting the wire to the sender .
    really annoying not having a working gas gauge , even more so after the previous guy said it worked . he filled the tank when I bought it and thought it was getting amazing MPG but
    just wasn't working

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