Hello To All In Forums Just bought a 1997 Park Ave and when the tank gets to about 1/3 from empty, the needle goes nuts, going from empty all the way up to full. Before I bought the car, had sat a while (4 months) without stabilizer, so I am trying some Chevron Techron Concentrate to hopefully clean the fuel system up. If all else fails, would I be correct in assuming that the fuel pump sending unit is faulty? Anyone got diagram of location and any info to replace would be helpful!
Also where is the fuel filter located on this non super charged 3.8?
Here is a shot of my new to me ride!

Nice looking car the fuel filter is located under the body on the driverside about halfway inbetween front and rear.Also it sounds like the fingers on your sending unit float are worn and when it gets that low it doesnt know where it is anymore.My 97 lesabre has the same issue

Thanks for reply. Will have to get the FSM for this car. So glad to hear it has an external rail filter easily replaced.
If the sending unit float is sticking possibly beside the Techron Cleaner, I could try adding some (top oil) like Lucas upper cylinder lubricant with injector cleaner. That might get the float un stuck in a hurry....
I was concerned that this may be an electrical sending unit issue though.

The float is not sticking. There are copper contacts that move across a grid of copper contacts, and their relative position tells the sending unit how much gas is in the tank. These copper contacts degrade and result in the problem you are having. The fix is to pull the fuel pump and replace the sending unit.

Thank You! will replace it then !
Besides Napa or dealer is there an online recommendation for Canadian Parts /GM/?Buick ??

i like to do the whole thing while ive got to drop the tank.

I buy everything from amazon, but their search sucks nothing ever come up, you have to find the part numbers and search them on amazon.

delco sending unit FG0041
delphi sending unit MU1819

there is just the level sensor sk1018, but like i say unless you have a access panel (pretty sure you dont) gas tank is a job i only want to do once.

I don't know which cars do, and which cars do not, have an access panel in the trunk to get at the fuel pump. Pull the trunk liner and look for an oval shaped metal panel about 9" by 6" on the floor of the trunk in front of the spare tire well.

im guessing 2000+ for H and W body

You are probably right, but I honestly don't know. Takes a minute to find out for sure though.

I just changed out my fuel pump and sending unit on a 97 PA.
No need to drop tank. You have a panel in the trunk to gain access. and I figure that if the sending unit is worn out the pump isn't far behind get them as a unit an change as one unit. my gauge is now rock solid.