My 1988 300ZX, I'm smelling gas, dying, have to give it gas to get started

Well, since you've replaced the vacuum lines, I'd check the fule delivery system. It's possible that too much fuel is travelling to the fuel injectors (or jets)... But if you need to pump the the throttle to start it sometimes than it could be the throttle body itself. Check the butterfly on the intake manifold. Your car has a mechanical linkage throttle, so you can easily open and close the butterfly and ensure that it in fact is opening properly and just as importantly, closing to just the right position on idle.