'89 IROC 305 TPI will no idle/hunts for idle

I have been this at awhile, the car has been sitting for a long time, partly because of this problem and no time, so it just sits in the garage. This is the original engine/tranmission, the car is pretty much bone stock, I have owned it from new. the problem I am having is idle, it will not idle properly, period. It will hunt for its idle, up and down, soemtimes it will stall, other times just up and down. When you first start it cold, when the ECM is running in open loop, the car idles perfectly. When it starts warming up, it will begin to try to idle down and simply it cannot. Injectors,TPS, IAC, EGR, O2, MAF, CTS, ECM, Intake gaskets have all been replaced. No vacuum leaks, good compression. I am stumped. I want to see if anyone else has a problem like this too. Recently I took it on the highway, and a code popped up 44, lean condition. A lean is usually a vacuum leak - I don't have one. When driving and anything other than idle, its fine.

Any suggestions would be greatly appreciated, I'd like to get it running properly, even though winter is coming. Its stored now, but I do take it out in the winter every few weeks or so jsut to keep things from freezing up.

thanks in advance!

with the problem only occuring in a closed loop state, and with all the mentioned electronics replaced, no vacuum leaks, code 44...wow, i'm just as confused. did you d/c the battery to reset the ecm? maybe the ecm needs to go thru the relearn process. if that doesn't work, then it has to be an inadequate fuel issue. clogged or failing injectors.