Hmmm. next time this happens, take both ground sides of your jumper cables. hook 1 to the neg battery terminal and the other end to a great ground with no paint or the starter itself. What your doing is duplicating the ground cable. If it starts, u got a bad ground cable. On the fuel issue, take the gas cap off carefully when problem is present, Is there pressure? run it without the cap, does it still happen? It should still crank tho regardless of the fuel. Unless its filling cylinders like previous stated. But more symtoms would be present.
