Odd problem

[2000blazerls]

My truck has been running fine. This morning I go out to grab something befor eI head to school. I crank the truck from the passenger side. It was kinda chilly. The truck started, studdered, and almost died. After a couple of seconds it finally picked up and idled correctly. Well I let it warm up while I get ready. About 5 mins. I get in it and I have about half the power I should. Really noticeable loss here. Well I assume my cat or something exhaust wise has fallen off maybe. I pull into a parking lot and look under the truck, everything where it should be. I kinda panic. I turn the truck off and turn it back on. Now it runs fine, no skip and full power again. What could have happened? And why did it fix itself? I just want to make sure nothing is broken and I make it worse by driving it. I would rather know what the problem is and fix it.

Thanks!!

Just for those who do not know me, it is a 2000 Blazer LS 4.3 2wd.

[nickledimed]

May have been a stuck choke, how cold are we talking?...it could be a number of things. what I do every year along with winterizing I also wash the engine either while cold or while running and I coat everything plastic and rubber with silicon and I coat all mechanicals with some type of lubricant.
JM2C

[2000blazerls]

Well it was cold for Albany, Ga. Maybe 40ish.

[93LT]

It wouldn't have been the radiator clutch fan not disengaging until you shut it off would it? Did it sound like it was a louder engine roar from the engine compartment than usual?

[2000blazerls]

No, I do not recall a louder sound from the engine but the exhaust was louder than what it should have been though, which is why I checked it. But it went back to normal after restart.