Okay.. I THOUGHT I had the problem licked, but it turns out it was just the cold air.
So.. I've been trying to reason through this myself. Bill and Pat really made me sit down and RTFM. They let me bounce ideas but that was about it. The net result was me figuring out how to use the damn FSMs
So anyway, one of the diagnosis paths lead me to fuel pressure. Yeah my fuel pump is weak, but its just barely within spec. So that was out. I then moved on to ignition. All coils are testing out (we'll ignore certain other funny things I noticed there for another thread.)
Next thing was check the TPS. On the way home from work, I hooked the scantool up and did the one arm WOT runs and noticed I was never getting more than 2 volts on the TPS... WTF? Called up Pat and told him what it was and he said, "That ain't good." So after work, I did a proper diagnosis (Ignition on ON, slowly increase pressure on the pedal) and found that the TPS would get to about 2.8 volts then suddenly tank down to 1 volt. WTF x2? Had fun switching the TPS (I'm sure Bill and Pat will make fun of me here) and the net result is 4 volts at 100% throttle with no dead spots.
I'm not sure if this fixed it as I have to wait for the morning for a test drive, but I'm feeling pretty confident this should be resolving the problem.