Fidle is connected the auxilary air regulator on top of the intake manifold, it might require a relay though, since it is a heating element, then again, it might not, I haven't done it.
What sucks is by now, most of these are out of spec or not functional anymore.
People seem to like Techedge WBO2, you don't even need one with datalogging since you can do that with MS, which is a lot cheaper.
If you use all of the stock EFI harness, you shouldn't need relays and fuses, except for the fuel pump I think. You don't even need a flyback board, since the 280z has injector resistors already.
Good luck!