What needs to be done is to look at live date to see if there really is no rpm, also sync and ficm sync needs to be looked at, it could be the wiring to the crankshaft sensor also. Test the wiring from the crank sensor to the pcm first, the pcm is located behind the drivers side battery.
Wiring click here
What is the IPR percentage and ICP pressure reading while cranking?
Normally when we receive all 8 injector circuit codes the FICM is needing to be replaced, (fuel injector control module). See if you have FICM MPWR pid in your scan tool, see if this voltage is above 45 volts while cranking the engine over. If it isn't, more than likely the FICM will need to be replaced.
Yes, remove the coolant bottle towards the drivers side, no need to drain the coolant, on top of ficm there is a plate 2 screws, remove this, using a DVOM set to DC volts check the screw closest to the drivers side for a 4 screw ficm, do not let the test lead ground out on the side of the case or the ficm will be shorted out and need replaced for sure. Turn key on, check voltage, should be more than 45, usually 48 volts, then have someone crank the engine, as this will load the power supply inside, if the voltage drops below 45 volts while cranking, the ficm will need to be replaced.
Since this all happened after alt replacement, have all the fuses been tested?, check the ICP sensor on the passenger valve cover, maybe this became disconnected, let me know what you find, thanks Steve W
I would first remove the secondary fuel filter cap on top of the engine, turn key on and see if the fuel flows in fast, to check the fuel pressure you need a special adapter and pressure gauge. Here is what the tester looks like.