'00 Grand Vitara has stumped the dealership

I have a 2000 Grand Vitara JLX with a H25 motor. my issue is, on cold start-up, it wont idle, it goes to 1200 and then dies. I am a student at Universal Technical Institue, it has stumped me, our lead-diagnostics instructor, GM/Isuzu Tech of 20 years, the dealership (original owner 7 years, maintained by dealership for all 7) and my wallet. Ive thrown parts at it, and still the same. New IAC, plugs, coils (about $900), alternator, fuel pressure regulator (2 recalls), TPS, etc. For some reason it does not have any saved DTC's. Everything BUT a new PCM. The diagnositics say "Replace with known-good PCM and Retest" I cannot get ahold of one. I cant see how its a PCM, if its only on cold start-up. I have a garage and inside(around 11am), it doesn't do it. at school its warm all day, won't do it. Finally, at night, when im getting out of work, if its chilly (around 60F) it happens. Tonight I cranked it 9 times. Started on the 8th, put into D, and the load of the trans killed it, finally, after warming, it ran. It acts like it has a carburator with a bad choke circuit. I've follwed all of Suzuki diagnositcs to every step, even used a Suzuki Tech2 scan tool, which i never have when it stalls to check the code. The dealership doesn't have a PCM, and will not order one on a "hope". Someone has had to seen this!