What causes the fuel gauge on a 2000 olds bravada to fluctuate?

Answer 1

That is sooo funny. (you might want to read from the end) I have the same problem with mine. I had to remove the fuel level sender unit to replace the fuel pump (it's all in one unit) and knowing that I had problems with it I checked it out. I found some "plaque" on the sensor connectors and a slight miss when trying to read through the entire span of the gauge. I cleaned and rebuilt the gauge sender and periodically tested it while waiting to finish the fuel pump assembly. While putting the unit back into the car,I plugged the unit back into the wiring harness and tested the gauge again. I had figured it was not in the dash because of the way it had still responded to adding fuel. THere were no problems ....the dash needle corresponded to the gauge level.(this was done in freezing weather ,please be mindful of). However shortly after placing it back into the tank,it started it's old "bouncing" problem. I don't think the problem is a bad float because that typically leads to generally high or low readings.I think it may be caused by a slow reading curcuit from the sender to the dash gauge (or even dirty connections). I wonder once in a while if it is in a bad position in the tank and vulnerable to fuel splashing around.