Are you sure it's getting fuel? Can you hear the fuel pump (near the gas tank) run when you turn your key to the on position? If you can't hear the familiar hum of the fuel pump with the ignition key on (but without trying the starter), then I'd check the fuse for the fuel pump. I had a friend with a six-cylinder 280SE that wouldn't start, and it turned out to be a corroded fuse. Good luck.