Join Date: Sep 2000
Location: Shrewsbury, MA, USA
Wire to your temperature sender in the engine has probably fallen or been taken off.
GM gas gauges act this way all the time. I've yet to get a car that has a gauge that has a linear output to it. Alot of it has to do with the shape of the gas tank. A tank with a flat top and a tapered bottom will always cause a gas gauge to decrease quicker from half to empty than from full to empty, because there is not as much gas per inch of tank height the lower in the tank you go. I'm not up on the shape of a 3rd gen Camaros tank, but I would bet that it has a sloped bottom to it.
Another thing that coould be happening is that your sender arm is bent so that the float can not reach the top of the tank when the tank is full of gas since there are mechanical stops that prevent the arm from moving beyond a certain height. It may only be able to get within an inch of the top, and then just stays there until you use up that amount of gas. In this case you might use up 3 or 4 gallons of gas (depending on how far from the top of the tank the sender is stuck at) before the gauge comes off the full peg.
Just get used to how your particular gauge behaves, figure out how many gallons of gas you have in the tank and your mileage and how far you've driven since the last tank full and you'll have a pretty good idea of how much gas is in the tank at any one time.
1969 Indy Pace Car
350/300HP RPO Z11