Tank Filler Pipe And Cap problems of the 1997 Chevrolet Suburban

1997 chevy Suburban in-tank fuel sending unit fire: bought vehicle used with 88000 miles. Events leading up to the failure / burn up of the unit included intermittent fuel pump and fuel gauge failure, had pump replaced by patrick GMC, problem persisted, had dealer wolf Chevrolet check fuel pressure throughout system (ok). Also noticed an intermittent burning smell. I then purchased from the dealer a replacement sending unit and another fuel pump, as soon as I took the sender out of the tank it was obviously charred and the modular connector burnt to a crisp, wires completely exposed with the insulation gone partially disintegrated the abs plug. This thing got really hot repeatedly. The lower explosive limit was luckily never reached within the tank or there could have been a spontaneous explosion, especially if the tank lost its seal and allowed outside air inside, (such as when the tank is empty and is pulling vacuum), for instance unscrewing the gas cap in ideal conditions next to a gas pump with a 44 gallon tank void sucking in as much oxygen in as the filler tube will allow, and hitting that glowing red hot sending unit. Old part is in my possession and is the original factory sender. Incident date is approx. When I performed the repair and discovered the burned up sender.