GMC Repair: buick century fuel guage problems, fuel needle, buick century

Question
I have 2001 buick century when I start the car and ideal for awhile the fuel
needle drops to empty mark, also while driving it will drop to empty mark. All
other gauges read normal and it only goes to the full mark and empty mark
reads no marks in between. What could be causing the fuel gauge not to be
reading accurately?

Answer
could be a faulty fuel level senxor in the gas tank, or a broken baffle in the gas tank that is shifting as the car moves cause the float are to be restricted and not showing the proper amount of as.  Either way the tank will have to come out to inspect and check