Update: This did NOT fix the issue. The problem is most likely related to a ECU reflash but not conclusive. I fixed the problem by calibrating it manually to my AEM Infinity EMS and displaying the fuel level in my CD-7 Dash.
After I upgraded the fuelpump in 2017 my fuel level gauge started acting up.
I ran out of fuel when the gauge showed 1/4. This happend several times causing a lot of grief.
Based on reports on m.net this is pretty common after changing the pump.
During the winter a managed to get enough motivation to have a look at the problem.
The sending unit is exposed to the fuel as it's being part of the assembly that submerged in the tank along with the pump.
All I did was to inspect and clean the contact surface for the brushes that moves when the fuel level changes.
I also made sure the level arm was all free without any chance of touching other parts trough the operating range. I looked ok but i slightly bendt it outwards to be sure.
So far after a couple of tanks of gas it seemed to have fixed the problem. My guess it was the arm and not the level sensor itself.