Bouncing guages

My 93 grand am gt with the 3.3 all the gauges kind of bounce around they never really give and accurate reading they are always bouncing back and forth. I replaced the oil sending unit to try and fix the oil pressure gauge but that didn't work so if anyone has any ideas that would be great

I have the same problem the oil gauge is pinned all the way to the right and the temp never goes above the quarter mark...thanks Glenn