So, the resurrection of the '92 has been completed, and after a few tanks of fuel and the liberal addition of SeaFoam and new oil, she runs like a total champ! Until this morning, that is. Start her this morning (it's a little cooler today than it's been for the past week or so) to take my Daughter to high school, and she fires right up....except now she's revving up-down-up-down-up-down in about 1 second intervals. Shutting her off and restarting doesn't clear the problem, nor does giver her some throttle. The Princess is giving me the 'evil eye' as if to say: "Why am I riding in this piece of crap car?" and asks me: "You got ghosts?" I'm beginning to think she's on to something. I figured I'd drive it to see if it clears the problem....and it does not. Still idle surging at stop signs and traffic lights. Drop off the Daughter, head to work and after about 5 minutes or so, idle settles down, is smooth as butter....and the problem is replaced with a "check engine" light. Otherwise car runs fantastically!

Query: I'm assuming that there is some cold-start valve in the system that malfunctioned. That being said--

(a) Where is it, if that's the problem?
(b) How big of a PITA is it to R and R?
(c) Can it be cleaned and replaced?
(d) Am I full of beans?
(e) How do I reset the Check light or, like my other vehicles, will it reset on its own after 3 no-fault drives?

Thanks, as usual!
Brad