if it runs with the throttle open a bit and dies when it's let off; to me that points at iacv. Have you looked at the wiring for it?
it seems unlikely that the one you initially had installed and the one you transferred off your old intake manifold would both be malfunctioning. Did you clean the old one out before using it. I doused mine in throttle body cleaner when i swapped it. All kinds of gunk came out.
you could look for vacuum leaks but that's not always easy to do when the car wont stay running. And I don't believe that would cause a car to die out.
when you do have it running can you get it to stay steady at around 1k rpm by using the throttle?