I suspect that the ecu is not seeing a tach signal, so it doesn't inject fuel. Test for a tach signal at the ecu while cranking. Check wires from coil - to ecu. You stated that there is no movement from tach while cranking, right? Get the fwm download and look at the fuel system wiring in the mpi section in vol 1. Trace the wires from coil- to tach and ecu. Pay special attention to the gizmos on the coil bracket besides the coil, and follow the tests for the power transistor as well. The gizmos on the coil bracket condition the tach signal for the tach instrument, and their wire insulation gets very brittle and if they crack, vibration breaks the wire via fatigue at the crack.

Do you have spark with the rebuilt ecu?

Not responsible for advice not taken...