It sounds like a wiring issue I agree, but the pcm still has to ground the injectors while cranking. Considering the fact that you can't communicate with the pcm along with the other symptoms, it sounds like there is a faulty power or ground circuit for the pcm. It also sounds like this problem began before the new TB was installed although I would still check the 5v reference circuits with the sensors unplugged. I can't get to a good wiring diagram at the moment, but considering all present symptoms it points to something pcm related like wiring, fuses, relays, terminals, ignition switch, etc...... Since the ignition operates in bypass mode during cranking it should still have spark while cranking.