It's not uncommon for the sender to be toast.... I took mine to a mechanic to fix the gauge cause I just didnt feel like doing it... I assumed he'd put in a new sender and then would be it... he calls me later that day and tells me the gauge on the dash is broken...and he'll try to find a junk yard peice... after a couple days he hasnt called so I asked what's going on... he said.. they'er tough to find etc.... I tell him to forget it.. I'll just deal...
fast forward 2 months.. I go home to visit my parents.. my dad runs an auto repair shop, so I put it on the lift and I pull the harness on the sender and my dad grounds the hot wire while I sit in the car.... the gauge after a couple seconds SLOWLY moves the full range.. when he ungrounds it.. it moved back... the anti slosh mechanism keeps the needle from jumping around when you go up hiills and around corners and stuff.. it basicaly delays any sudden movements so the needle isnt all over the place...
so I dropped the tank to replace the unit and there's thier wierd piece of metal that's right inside the hole... doesnt look right.. I pulled the sender and it's missing something.... THE FLOAT.... as it turns out.. one of the baffles in teh tank.. broke loose and took out the float on the sender... no wonder it didnt work... anyway.. .I ended up getting a new tank and a new sender... I didnt the work myself... so I saved alot of money.... I just thought I'd share the story....
it's POSSIBLE it's not the sender... but you should be able to test it easy enough.... while you're dropping teh tank.. you might wanna get a higher vol fuel pump.... I wish I had.... it only makes sense since it's a pain to do... another tip... try to make sure the tank is as empty as possible.. it's alot easier.
When I fill my tank the needle goes well past full.. it stays there for about 50 miles and then starts to come down normaly.... I dunno if that's NORMAL .. but I dont find it to be a problem... cause it works the rest of the way down... give or take.. it's not like the fuel gauge on a 747, there's alittle room for error
-as