Close



Results 1 to 7 of 7
  1. #1
    FEP Member
    Join Date
    Dec 2005
    Location
    portland oregon
    Posts
    489

    Default fuel gauge reading wrong

    Ok so Iadmit it , i sinned lol. I swapped the interior in my 86gt to all black 87-93 but now im having probs with the fuel gauge reading wrong. I never swapped out to a newer sending unit, and when i put 5 gallons in there itll read 1/8th tank which I know is wrong. the gauge on my old style instrument cluster worked great with the sending unit thats in there right now. Its the sending unit isnt it??

    thanks

    Drew

  2. #2

    Default

    Do a search for fuel sender here, this has come up before.
    Marc aka tripice351. 84.5 GT-350 2.3T, 89 Vert 5.0, 54 F-250 390FE, and a few more..

  3. #3
    FEP Member
    Join Date
    Dec 2005
    Location
    portland oregon
    Posts
    489

    Default

    so i found these resistance specs

    79-86: 8-12 ohms full, 60-86 ohms empty
    87+: 145 ohms full, 22.5 ohms empty

    Another thing to note is that if i fill the car up then the gauge reads full, maybe my sending unit has a dead spot......so frustrating

  4. #4
    FEP Member
    Join Date
    Dec 2005
    Location
    portland oregon
    Posts
    489

    Default

    I did a search and some people say that it should read backwards, which is not happening in my case and some other people have said that in 90-91 the sending unit is dif than the 87-89, my harness is from a 92 5 liter. thatd make sense because the instrument clusters and harnesses are dif for 87-88, 89 and 90-93

  5. #5

    Default

    The later aeros have an "anti slosh" module behind the dash somewhere. It's often the culprit of a non functioning gauge.
    '88 Mustang GT convertible, T5, 3.08:1 gears, A9L Mass Air conversion, Fenderwell Mac cold air intake, Ford 70 mm MAF meter, aftermarket 70mm throttle body and spacer, Explorer intakes, GT40P heads drilled for thermactor with Alex's Parts springs, Ford Racing P50 headers and Mac H-pipe, Magnaflow catback, Walbro 190 LPH fuel pump, UPR firewall adjuster and quadrant with Ford OEM cable, 3G conversion ('95 V6) with small pulley ('94 Tempo), Taurus fan, rolled on Rustoleum gloss white paint, more to come...
    Past Four Eyes: Red well optioned '82 GT 5.0, Black T-top '81 Capri Black Magic 3.3L 4 speed, Black T-top '84 Capri RS 5.0 5 speed. Over 200,000 miles driven in Four Eyes, and over 300,000 in Fox Body cars.

  6. #6
    FEP Member rbmead86's Avatar
    Join Date
    Dec 2004
    Location
    Lithia Springs GA
    Posts
    190

    Default

    "Bump"
    Im having the same Problem.
    Have You Registered your GT?
    www.mustanggt.org

    1986 Mustang GT Vert
    1985 Ford LTD SSP
    1977 MGB Vert

  7. #7

    Default

    Quote Originally Posted by D347643 View Post
    so i found these resistance specs

    79-86: 8-12 ohms full, 60-86 ohms empty
    87+: 145 ohms full, 22.5 ohms empty

    Another thing to note is that if i fill the car up then the gauge reads full, maybe my sending unit has a dead spot......so frustrating
    I put those specs up. The resistance vs tank level is essentially reversed for 79-86 vs 87+. The sender AND gauge must be from 79-86 or 87+. You cannot mix them. The anti-slosh module is basically a chip that 'averages' the instantaneous resistance output from the sender so that the gauge readings dont fluctuate. Averaging algorithms are very common is instrumentation.

    Paul
    1978 Mercury Zephyr 4-dr / Holley 600 vac sec carbed 1989 5.0L HO with Edelbrock Performer intake / MSD-6A / T-5 / 8.8" rear 3.27:1 / Mustang 5.0L brakes, suspension, steering / Dual exhaust / Mustang 10 hole wheels / P225/60R15 Goodyear Eagle TR

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •