and when u put gas in the intake it starts every time without problems? id say check ur fuel filter, pressure regulator, fuel lines, while ur at it remove ur fuel rail pull the injectors clean them all off, umm....(scratches head) if u can find out what kind of engine he had b4 and when he swapped out his car did he swap in a new ecu with it, the only other thing i can think of is he's running an ecu programmed for dpfi with a mpfi hf fuel rail? or some unique problem like that, id say figure out the type of ecu and the engine model and post it on here so we can make sure its compatable, then again it can be a completely different problem that is being overlooked, oh and btw ur intake manifold is definitely not built for fuel so i wouldnt do that very often