I just bought a 1994 infinity J30 and it wont start.

If you Infinity is manual transmission, I would say your clutch switch may be faulty. If your car is automatic, the neutral safety switch may be at fault. Have you tried to start your car in neutral? Try it. If it starts you may need a neutral safety switch, some import auto makers call them inhibitor switches. Go online to find a wiring diag. of the "starting circuit" (Auto Zone / Advance, may be able to help you with this) this will show you the path that the "S" terminal takes. Hope this helps you.