Fuel Gauge Problems

[Donster]

I have replaced the circuit membrane behind the pod. Everything works now, with the exception of the fuel gauge.I filled up the tank, disassembled the pod so I would have access to the needles (previously, the gauge needle was swinging all the way to the right, past FULL), removed and moved the needle to the actual FULL position. As soon as I drove the car, the needle slowly began to move all the way to the right again, now almost in a horizontal position, i.e. way past FULL again.Is this an indication of a broken fuel gauge?
Thnx,
\D

[Raydar]

When my car sat unused for a long time, the sender built up a very high resistance, which caused the gauge to peg whenever the key was on. (Higher ohms = more fuel. An open circuit = infinite ohms = maximum fuel indicated. )

Is that where the gauge always rests? Above full? Or does it work sometimes?

The three pins on the gauge are 12 volts, ground, and the sender. If you can figure out which pin comes from the sender, you ought to be able to unplug the gauge assembly, and measure from the socket contacts with an ohm meter. It will be between the sender lead and ground. (Or, preferably, between the sender lead and the gauge ground.) The sender will show ~zero ohms  to ground, at empty, and ~90 ohms to ground, at full. Approaching "infinite" ohms - or at least way more than 90 - if the sender or sender circuit is bad.

[GTRS Fiero]

I strongly recommend getting your gauges actually recalibrated.  I did the guess thing, but mine were off.  I had my speedometer rught at 60MPH, or at 0MPH, but couldn't get it right both places.

[Donster]

I thought the speedometer is controlled by the VSS, no adjustment needed?

BTW: new (used, known working) back-lit temp/fuel gauge on the way from Texas.

[GTRS Fiero]

Not on the V6, for sure.  Mine was off.  The VSS just sends a signal; the needle still needs to be correct.