Fuel gauge dropping to zero slowly

Hello all, this is my first post here *smile* though i've been skimming for quite some time..without all the helpfull comments here I would still be wondering why I had coolant in my oil (that was a pain to replace that gasket) and why my speedometer kept bottoming out and causeing me to downshift (VSS)

my car is a 96 (96 acording the the VIN, but is listed as a 97 through several sources so i'm not sure) Chevy lumina, 3.1

ok, problem is, when I hit the gas station, put in lets say, ten dollars...the gauge reads properly at about 1/2 tank or so from empty...but over the course of the next hour of driving the gauge will drop slowly and bottom out completely..not to rise again untill I put more gas in...even though I know there is still gas in the tank..I've been driving on mileage...but I have a road trip coming up and I need to get this ironed out.

any help would be great. thanks in advance.

***I'm not sure of this***, but, I think starting around '97 there was a new type of fuel gauge module that's purpose is to iron out the fluctuations in gauge reading when cornering, stopping, etc. Sounds like something it might do. Maybe ask Richtazz.

That or theres a hole in the float and its filling with gas while your driving it. When the tank gets empty again it drains back out until you fil up. Then it repeats the process. Deff. Sounds like a sender unit problem to me.