Grandfathers Thunderbird has sat for 5 years. I can hear the fuel pump build pressure, replaced fuel filter. After cranking on it, eventually it will start. When it starts to die, I give it some more gas, RPMs increase but it doesnt run much longer. I do smell gas after it dies. After a couple times of this the battery has to be recharged. I hook it up to a jump at 55amp's and it will start once more and then die. Also, I did drain the fuel and put in half a tank of new gas and 1 - bottle of gas treatment. Before breaking my pocket book, if someone could please give me some insight on what might be the issue. It is much appreciated as I dont want to see this car taken to the salvage yard.