It sounds like mine when it had a leak in the MAF sensor, but, mine didn't smooth out.
Could be the plastic duct from the MAF to the Intake -- could be cracked. Cold air constricting the duct could cause the crack to be open, then, the car warms up and the crack closes (this happened to one member, nearly drove 'em nuts 'til they found the problem).
Also, I don't know if Colorado does the "gasoline switch" like some states do, but, sometimes the so called "clean gas" causes similar symptoms.
There's also a TSB for 92's regarding Gasoline Volitility and cold engine starts -- there was a ROM chip upgrade that was supposed to get rid of this on 92's.
http://members.tripod.com/quick_svx/.../42749371.html
And, yes, let's hope it wasn't a "bung up" on the timing belt. Wouldn't be good.