Are there any Ram Jet fuel injection people...

[Firehawkslp]

The "smoke " when it dies is most likely fuel washing back. I would run the valves making sure there not being held open. Have you pulled all the plugs to see if all the cylinders are rich. One leaky injector could cause the ecm to lean all, yet still smell rich. This would explain the ruff running, the backfiring and the stalling. Also check that the plug wires are well seprated espcially where they run parallel to rule out cross firing, also check pwr to the ignition most modern hei and dis run on a full 12 v . One last thought have you checked for intake leaks ( spray carb cleaner, wd-40, brake cleaner, ect. along the intake matting surfaces) at the heads, throttle body, if the engines running changes, congrates it's a leak.
These are things to check other than the ecm related.

[RatPwrd]

I bought a pair of iron vortech cyl heads and a ramjet manifold to install on my dad's streetrod.We got it all installed and running with a DFI computer and had a little trouble programing it.We had trouble with it back firing every once in a while.Come to find out it was a VERY BAD valve job from the factory.We pulled the motor and freshened the short block and redid the valve job on the heads and ran it on the dyno to program it and it made 340hp and 390 ft lbs it runs great a nice reliable fun to drive 350 for his hot rod truck.The other thing is on his truck with the DFI it is REALLY sensitive to the battery being fully charged up,and we had to put a powermaster 140 amp alternator on it to charge enough at idle or it would really act up .Good luck with your project