1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

Fuel Guage Problems

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Old Nov 19, 2007 | 02:48 PM
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Fuel Guage Problems

My Fuel Guage will not work. Any idea's would be helpfull
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Old Nov 19, 2007 | 03:25 PM
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If it's only the fuel gauge is the only thing not working, then it's definitely not a fuse problem. Check behind your left rear wheel well. You should be able to access the wire connector for the fuel sending unit. Take it off and spray it down with ElectroMotive spray and dab it up with dielectric grease. If it still doesn't help, you may have a wiring issue other than that.
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Old Nov 19, 2007 | 04:14 PM
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Your fuel sending unit may be bad. The unit has an arm that runs across a copper coil (IIRC). Sometimes the coil will get rubbed so much from fueling that it wears the copper coil. There was a car that only read full, then a few miles down the road it would read empty.
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Old Nov 21, 2007 | 04:46 PM
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if it's the sending unit what is the easiest fix?
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Old Nov 21, 2007 | 04:54 PM
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replace the sending unit
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Old Nov 21, 2007 | 05:09 PM
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Check to make sure that the ground between the fuel tank and chassis is actually good. That's the problem I had when I replaced my tank.

If I remember well I tested the gauge inside the car from the connector at the gas tank. I shorted two of the wires together and the gauge indicated full, so I knew the gauge in the car was good. Afterwards, using a meter I tested the sending unit following the service manual procedure.
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Old Nov 21, 2007 | 05:09 PM
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I guessing that means droping the tank. thats what i was trying to avoid.
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Old Nov 21, 2007 | 06:33 PM
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I don't know what kind of 7 you own, but if it's an -SE, you don't have to drop the tank. IIRC, the sending unit is right behind a plastic panel behind the left rear wheel. Remove the wheel and panel and you should see it. Tho, just hope the screws that hold the sending unit is aren't frozen. Then, you'll have to use a Dremel to carve new notches for a flathead screwdriver to twist them out. Use loads of PB Blaster.
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Old Nov 21, 2007 | 06:35 PM
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i do have a se. thank you very much
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Old Nov 21, 2007 | 07:25 PM
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I had to replace the sending unit. As long as it isn't too rusted it's pretty easy. But expensive,
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Old Nov 24, 2007 | 08:09 AM
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okay, i took off my rear left tire and looked eveywhere i could and didn't see anything. i can't get anywhere with this fuel guage problem. can some one please help i'm tired of not knowing how much gas i have
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Old Nov 24, 2007 | 08:11 AM
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Did you also remove the plastic panel that is behind the wheel? Once you remove that, you can't miss the wires leading into the sending unit. I know this because earlier this year I replaced my gas tank with a new sending unit as well.
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Old Nov 24, 2007 | 08:18 AM
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inside of my wheel well is all solid, no panal, by the way i have a 84 gsl se with a 12a stuffed in it
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Old Nov 24, 2007 | 08:22 AM
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Huh. IIRC, all GSL-SEs had 13Bs stuffed into them, not 12As, unless the previous owner did a swap. And, all -SEs had one style tank.

Can you take a picture with the wheel off to see what you're dealing with?
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Old Nov 24, 2007 | 08:25 AM
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they do, i found the car with no motor in it and had a strong 12a with few mods so i stuffed it in
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Old Nov 24, 2007 | 08:26 AM
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sorry no go on the pic. i'm on a work computer right now, and internet at my house is down for the time beeing
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Old Nov 24, 2007 | 08:33 AM
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Even if the previous owner installed a 12A, he should've left the -SE tank in place. There should be a plastic panel in the back right corner (so to speak) of the rear wheelwell. Removed by 3 (or 2?) bolts, it drops, and you see the fuel sending unit.

Here is a link to the difference in fuel tanks.
https://www.rx7club.com/1st-generation-specific-1979-1985-18/84-85-fuel-tanks-facts-416682/

Looking at the tank on the right, look on its left side, behind the filler tube neck. See that opening? That's where the sending unit goes. Easily accessibly through the panel on the GSL-SE. ALL -SEs have that panel.

Last edited by 85 FB; Nov 24, 2007 at 08:48 AM.
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Old Nov 24, 2007 | 08:47 AM
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http://frosted7.com/katrina5.html
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Old Nov 24, 2007 | 08:49 AM
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thank you for your help
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Old Nov 24, 2007 | 08:52 AM
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Be sure to get a can of electrical contact cleaner made by CRC. Stuff is great for cleaning corrosion off.
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