Now I know fuel gauges in most vehicles are notoriously inaccurate (or at least not terribly linear) but my 95 seems to set a new standard!

When I first bought the car a month ago, it had a problem with the sending unit (the gauge read full all the time) which I corrected by disassembling and cleaning it. At least now the gauge isn't stuck on full all the time but it seems to read waaaay off. Yes, I was very careful when I pulled it not to bend the float arm at all.

Anyway, it stays showing full for much longer than it seems it should. As a matter of fact, with 1/2 a tank, it still shows full and with a 1/4 tank (a 20 gallon tank, yes?) it shows one bar less than 1/2. Not very linear and not very accurate!

Now I can live with it this way (I always reset the trip meter when I fill it up and go more by miles driven than the gas gauge anyway) but it'd be nice to have the gauge semi-trustworthy

 

My 95 is much the same gauge wise.
I had it several months thinking it didn't work and kept it full.
Went on a road trip reset the mileage so I knew I could go a long ways so I went far enough for the thing to go down.
At a little under half I had about a quarter of a tank and at three bars it went fast and low fuel light came on.
Very inaccurate till the end so I make sure to gas up just below a half.
Most GM products gas gages suc.
My 2005 trailblazer gage went out right after the warranty. Bummer!

 

If your ground is good, about the only thing left is the sending unit or the gauge. Sending unit is cheaper than replacing gauge.

 

My 95 acts the same way.

 

It's not a ground problem (no I'm not being cocky - I'm being logical) because the fuel pump works fine. It and the sending unit share a common ground in the harness.

As for the sending unit itself, I disassembled it (removed the nichrome winding from the holder) cleaned everything and even made sure the wiper spring provided enough tension. After reassembly, I verified the operation of the sending unit by measuring its response with an ohmmeter before reinstalling the unit.

 

If you are sure the sender is good, then you either have an open circuit to the gauge or the gauge itself is bad. What is the range of resistance from full to empty? Have you checked your ground to chassis. Had same problem with mine and in the course of the restoration, I forgot to hook up the body to chassis ground []

 

You're not reading my original post correctly. The gauge DOES work but is inaccurate. And while I don't remember the exact resistance reading (I *think* it was from roughly 0 ohms to 250 ohms and it was fairly linear) that the gauge is not always stuck on full indicated the sending unit is working. Well, in a fashion anyway.

Ground is good as well.

 

OK, then the only thing left has to be the gauge itself, which is part of I/C.