are you sure the ECU is getting the right power feeds from the key?
there is one line for power, so the ECU remains powered in crank despite lots of other things in the car that are not powered. Make sure the power doesn't go away when you're in crank.
your ECU fuse on the underhood fuse box may be wired wrong also... if it's only powered in Run the car will never start. (same problem, different area)