HELP - Wiring problems

[skswapman]

I've got a '89 nissan 240sx and I'm in the middle of installing an sr20det._ The harness was cut at the valve cover, and_I got the ECU plug piece, and_I got the ignitor chip off ebay,_And I'm waiting on an ECU from japan, so basically im splicing the 2 harnesses together._ There's a few wires im having trouble with...

pin 105 = fuel pressure control module - red/white, I have no idea where i'm supposed to hook it up

pin 109 = reverse electrical flow return circuit (alternator fail input) - red, wtf where does this go? does it hook to the alternator? i haven't checked that out

pin 111 = turbo boost pressure control solenoid (overboost cut?) orange/black, again wtf. does this even need to be hooked up.

pin 45 = ambient air temp sensor blue/white, This one puzzle's me It doesn't go to the MAFS....? whats an ambient air temp sensor? where is it anyone know?

Also there's a 5th wire coming from the coil packs by the igniter but not into the igniter, if i remember right its blue with red, now is this a ground or a power wire?

One more thing Do the grounds really matter, i mean if i hook up a sensor ground to an eccs ground that should be ok right as long as everything is grounded?