Samantha: "shutters" needed to be corrected but not "natural" or "ridding"?
Roachstr: It does sound like a clogged fuel filter, which is what Nick is talking about. We'd be more comfortable if you detailed what you did to diagnose it. Beyond that, might your fuel line be crimped? Have you done anything to the secondary injector connectors? How about an EXCVA that isn't opening?
Are you saying that the neutral light doesn't come on when in neutral or that the gear position indicator doesn't show "0" (or both)? Have you checked the voltage on the P and Bl lines at the GPS?