Hey all, I've been working to restore my 88 GT and tried a little bit of fabrication to save myself a little bit of money. I was able to make a universal fuel level sender work for me and wanted to share with the rest of you. My particular fuel float arm assembly was reading 0 ohms regardless of position and the adjustment screws did not help. I considered the option of getting a complete sending unit from the Fiero store, but wanted to see if there was a cheaper option available. Take my experience with a grain of salt because I am sharing this BEFORE I see that it works well in the car for a while. If this fails I will definitely be purchasing the Fiero Store option.

I was browsing ebay/amazon for a 0-90 ohm float arm and was able to find this one for a pretty affordable price at $28- https://www.amazon.com/Univ...r/dp/B07S77K2CF?th=1
What I didn't realize before this arrived is that this mounts backwards as compared to the stock sensor. Which caused some problems I didn't expect.




1. I started cannibalizing the old sensor by sipping the plastic tabs that hold the body of the sensor to the tack welded sheet metal backing. It took a little bit of light prying, but I was also able to remove the float arm from the pivot.




2. I then did my best to straighten out the metal backing and trimmed away the areas past the 5 holes that were in it.

3. The idea I came up with utilized the slotted piece from the universal sensor, I trimmed that using an angle grinder and bored out the holes on the original backing to accept the hardware diameter that same with the new unit. I used the top section of the slotted piece (which had 3 threaded holes) to mount that to the original sensor location.


4. I then had to use bolts as standoffs to space the sensor back enough to clear everything. I also cut out a piece of aluminum sheet to use as a backing plate for the sensor to mount to. It is a bit janky looking, but it seems to be functioning as intended.


5. I then trimmed the length of float arm rod that I needed. I probably won't be prefect measuring the entire depth, but I made sure I would get as accurate of an empty reading as possible.
6. The last thing I did was re-terminate the black and purple wires with ring terminals. I put the purple wire onto the sensor standoff, and fixed the black wire to one of the bolts I used as a spacer.


Fitting this back into the gas tank was tight. The bolt heads from spacer bolts were pretty close- I almost considered grinding them down. I also had to lower the whole assembly with the float in the upright position- so when I need to remove it I will need to put something down there to fish it out first. Electrically everything checked out. I read 0ish-90ish ohms between the purple and black wires at the yellow connector, and had a negligible resistance between the red and black wires. Fingers crossed I didn't do anything glaringly wrong and some people can find this helpful. If someone has found a better option for a universal sensor please link it below- something that swings the correct way would improve this a ton.

[This message has been edited by MichiganReefer (edited 04-24-2023).]

Nice writeup, only input I have is to make sure that the ring terminals do not need the plastic around them because they will probably be eaten over time from the gas unless they are fuel safe.

Thanks for putting this together.

Very true about the plastic! And hope some others find it useful as well.

All metal ring terminals soldered to the wire would be better than the crimp & plastic, Also better clamps are available for this project. (Dorman 800-308). The type you have will dig into the rubber fuel line eventually. And just in case, only submersible type fuel hose is used inside the gas tank. It's sold by the foot and it's expensive. Gates 27093 < check size. I can't tell what type you used.
Good luck on your project.

Spoon

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"Kilgore Trout once wrote a short story which was a dialogue between two pieces of yeast. They were discussing the possible purposes of life as they ate sugar and suffocated in their own excrement. Because of their limited intelligence, they never came close to guessing that they were making champagne." - Kurt Vonnegut

Crimping works just fine, you just need to make sure it's done properly. The stock wires are even crimped.

Yes, crimping works But Need good ends and tool. Go Cheap on either often causes problems.
Like?
Cheap crimps have weak metal and fail over time in this case can cause same problem cover in https://www.fiero.nl/forum/Forum2/HTML/146784.html Most Ends sold by Amazon and a lot more are very poorly made.
Cheap tool can't get good compression on any end, more so w/ Good ends like made by 3M and ends barely hold the wire.

Factory Crimps are installed by Air or Hydro crimpers and pressure they generate often result in near cold weld the parts and near 0 voids letting air etc in the connection. You can't generate the same pressure with most hand tools and why GM even recommends soldering some joints.

Example: One specific is Pigtail w/ New Plug to use new style ECT for ECM. Because Errors w/ iffy wiring will cause ECM reading coolant temp wrong and engine can run rich and other problems.

Other problem is any installing this or other replacement Fuel Senders often set so Empty on Gauge = Total Empty tank. That's bad enough on level ground but will have problems way sooner on any incline because Electric F-pump Hates running dry for any amount of time.
Even w/ Factory Setup, F-tank design make easier to have same problem when near empty but not as bad for most people unless live in "Hill Country" areas.

Even after fixing gauge clips and now get better readings, I still won't let tank to run lower then 1/8-1/4 because tank tipped driving up/down a small hill can make gauge and pump to see "empty" really fast.

Note that many tanks can't suck dry and not just a "Fiero" problem. Tank Baffles and more can block last 1/2 to 1 gallon or more depending on road your drive on right now. Most time my 87 say empty and fill w/o pushing only get 9-9.5 max. I only push empty many years ago till engine dies to reach 10 and tiny bit more. (Pushing to fill more can cause other problems now or soon as gas heats up and expanse.)

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

[This message has been edited by theogre (edited 04-26-2023).]