Recently purchased a 1988 Comanche with a 1998 4.0L swap. Gas gauge wasn't working and was always sitting on E with the light on. Previous owner told me it was the fuel sending unit. Replaced the sending unit/pump and the gas gauge worked till I took it to the gas station and turned her off. Once I turned her back on the needle was back to 0 with the E light permanently on. Occasionally the needle will go up to a quarter, but the light will stay on and the needle will return to E shortly after. Any ideas?