Between Clifford and I, we will keep you busy.
I think both of us are leaning heavily to a no-fuel situation. That should be your priority.
Your clue will be whether the engine makes any attempt to start (as opposed to just turning over). Even if you have a clogged intake (not too likely) or low ECM voltage, the engine should at least sound like it is trying.
On my DDEC III/IV I tried to start it one time with the batteries pretty low. It did start but really ran bad. I suspect that would be the case with DDEC II
Jim