Why does the engine miss on cold startup and not when at operating temperature?

2000 blazer 4x4 has new tuneup, new TPS, new IAC, new MAP sensor, checked EGR valve for carbon buildup, very little and function. Did not check for electrical, though. It was in closed position and seated when I pulled it. On cold startup in morning, starts fine, idles fine, idles down fine, when I start driving it, it has a severe miss until it reachs operating temperature. It runs fine after reaching peak operating temperature. It is now 78degrees in morning and 100degrees in the afternoon. Hope you can make some sense of this, and give me some solutions. Thanks, Robert