I have a 97 Buick Park Avenue and when the fuel gauge gets down to 1/4 of a tank the needle jumps around and will sometimes show it has a full tank and
other times it will go down passed empty and sit there for a few minutes and creep back to normal position. Is this a problem with the sensor in the tank or the gauge in the instrument cluster? Any information or help with this problem would be appreciated.

My understanding is that it is the fuel sensor unit, which is a part of the fuel pump and quite a project to replace. But...if you can't live with it. My 97 was acting up when the tank was full. Lately it seems to have stopped.

If I'm not mistaken the gas tank has to be removed to replace the pump assembly.
I hear the labor cost is about 200$+ A new pump about 250$.

Perhaps someone could post a more accurate price.

My guage is distorted. It takes alot of time to get down to a third but after that it goes quite fast.

Good Luck

You can save money by just replacing the level sending unit/float and not the complete fuel pump assembly. For a '97 PA the AC Delco part # is SK1018, Sensor Kit, Fuel Level. GM list is around $150 but there is an ACDelco Authorized Distributor located in Flint, MI that sells them for $85.00 plus nominal shipping charge. About a 1 hour to maybe 90 minutes DIY job.

http://i5.photobucket.com/albums/y186/lizzywiz/fuelsender.jpg

If I'm not mistaken the gas tank has to be removed to replace the pump assembly.
I hear the labor cost is about 200$+ A new pump about 250$.

Perhaps someone could post a more accurate price.

My guage is distorted. It takes alot of time to get down to a third but after that it goes quite fast.

Good Luck

Tank doesn't need to be dropped. There is an access panel in the trunk, under the trunk liner to get to the pump itself.