2000 Bonneville SE Fuel Gauge Problems

[the_iceman]

I've already posted about a problem with my heating system on my bonneville and thought I'd also ask about my fuel gauge.

About a year ago I moved from one house to another. My new house has a fairly steep incline where the car is parked. With the Bonneville on the up-hill slope it the fuel-gage usually showed a little 'less' gas than when the care was on a horizontal plane. No big deal about that one. But about 4 months ago I realized the fuel gage was not working appropriately. I know, based on the milage I drive, I had about 1/4 tank left, however the gauge started to fluctuate between 3/4 and FULL. I knew this wasn't true and went and filled the tank (I usually always reset the trip-o-meter) and the gage went to full. I noticed it seemed to be accurate in the amount of gas in the tank to the 1/2way mark. It almost seems once it goes below 1/2 it then starts to 'go back up'. Sometimes when there is say 1/4 tank left it will show 1/2 or sometimes 3/4 or even up to FULL. It might show 1/4 (for a few seconds or even a few minutes but then you can see it climb above the 1/2 mark and up to whatever 'resting' place it wants.

It seems ODD to me. When one starts the car you can see the FUEL GAUGE and the TEMP GAUGE run a full 'reset' like feature where it goes from the far left... over to the far right... and then back to the far left. Once it completes that it then seems to 'adjust itself' for what it feels the temp and fuel status are.

My initial thought on this is maybe the sensor in the tank is bad (for the fuel gauge) and is sending bad data to it?

Any expert thoughts on this one... and fixes for it?

[Doctor Bob]

Iceman, I recently viewed an article on bonnevilleclub.com/forum/ concerning your problem, the year was different but it will give you a place to start. They discuss installing a resistor in line with the fuel sender, they refer to a GM bulletin. When you go to the site click on techinfo on the top of the page and type in keyword "fuel gauge".