I have this problem slightly too. Works itself out in about 20 seconds or so - seems just like it might be burning coolant...BUT!,
I have checked my HG by pulling all the plugs, did a pressure check on it, and frequently check my oil (no sign of white). Pretty sure that isn't it. I was thinking I need to do some more TPS adjusting. (course it is 13 degrees out..that may do it).

I had been running the fuel pump jumper constantly on until it started getting cold. That really made the truck run bad on startup when it is cold out. It would almost knock for the first few on startup. Unplugged my homemade jumper and it made a world of difference for winter starts. Any ideas on that one Roger?