Lumina Gas Gauge

I just bought a 97 Lumina and when i first got the car it said it had a full tank of gas in it. But when i got gas it went from full to empty back up again and i have been having problems with my gas gauge, it goes up and down. Can anyone help me with this problem?

The float sensor in the tank tends to go out, especially with a car ten years old. My 1999 is already shot below half a tank, I use the trip odometer to judge when I need to fill up. The part itself is integrated with the fuel pump, GM won't sell you just the float and sensor. Most auto part stores won't do it either. Another thing to check, although not as likely, is the connector for the instrument cluster. Sometimes the contacts can bend and wiggle loose with time, making intermittent contact. But if this is a constant thing, i.e. it always goes to the same level around the same time as you fill up, then I'd put my money on the sending unit.

Some the dealers will sell the float and the sensor and the local dealer ship in my area does and orders it by the vin.GM does have problems with their sending units.You have buy the whole pump and is about $300.00.Go with one from Carquest,their fuel pumps are now made by Delphi whom make GM's fuel pumps and they did ditch Airtex since they were having problems with Airtex.It does say on the box with Delphi's logal.You can go to the dealer too,your choice.Stay away from Airtex and Carter,their fuel pumps are junk.Airtex does not warranty their fuel pumps 99.9% calling it installer error.Had one Carquest fuel pump which was an Airtex pump at the time quit on the spot.Ran the car in and would not start after replacing it,my father was angry about too.