I have a 1995 Cadillac fuel injection LT1 engine and I'm using a 1995 Camaro gas tank with the fuel injection pump and sending unit in the tank, just like it came from GM. I cannot get my fuel pump and gas gauge to work at the same time. I am using TPI gauges. I know the ground from the gauge needs to connect to the sending unit ground and with this connected, the gauge works fine but the fuel pump will not work unless I connect the tank/pump ground, same wire, to the frame. With the ground attached to the frame the gas gauge pegs to 'full' even with very little gas in the tank. When I purchased the Cadillac parts I also got the tank and it has 4 wires coming from the Pump Unit but this tank was too big so I'm using the Camaro which appears to have 3 wires, at least the part I can see, coming from the pump unit. I need to know if the Camaro actually has 4 wires and both grounds have been connected at the unit or what I can do to fix the problem. Thanks so much for any help. Bruce