[V8] still running issues.

[Paul DAnneo]

Hello All,
Well, I've just about given up. Work only allows me 2 hrs a week. Not enough for the slippery slope!
'91 v8. Still having running issues. I've changed alot. 
Car will idle. Won't accelerate. Acting like it's being held back. Smoking too. 
Changed ecu. Original was giving bad codes. New ecu was giving me 2231. Air leak in the IM discovered with spray. Replaced IM.
Still 2231. So disconnected the ISV. Code goes away. Cleaned ISV no luck. Code returns. Replaced ISV. Code went away. Car doesn't run any better, BUT no more codes.
Replaced air flow meter. Injectors, Fuel pump, filter, cats(cat light came on), knock sensors, ISV, Hall sender, plugs, wires,  timing all in order. There might be more. 
Just a few more q's b4 the wrecker...
I've seen issues with the trans fluid being low. Will this effect the running issue in P or N? Runs the same in/out of gear.
Could someone(wrench) mess with a fuel mixture? 
How about the speed sensor? Could it cause any of this?
Could an ecu from an earlier model effect the code reading?

I'm reaching here. 
As always, TIA....

Paul