The gas gauge reads empty after just being filled and after about 1/4 the tank is gone, it will finally read correctly. We were also having issues with starting the car. We needed to push on the gas while trying to start it to make it start sometimes. We had the fuel pump replaced and the gauge still wont work.
Why does the gas gauge not work? on 2004 Chevrolet Malibu
Either the connector is bad on the fuel pump module or maybe your new pump is bad.