Well, I give up. For now, anyway. Unless someone has some magic words of profound knowledge, wisdom, and common suffering. I've gone through everything I can think of and all suggestions (thanks everyone!) thus far with no effect, and applicable sensor readings seem to be as-expected. And still, 20's and below it starts great in the mornings, 30's and 40's it hunts and surges and almost stalls for a few minutes until it gets its sh** together, and no problems at higher temps. It's pretty much cold (hovering between uncomfortable and miserable) all the time now in the mornings, so by default the problem has deferred itself until the beginning of spring. I'm sure I've missed more than a few things, so keep the thoughts and advice coming, somewhere someone has experienced this same phenomena and fixed it by...........