Originally Posted by funugy
Looks like your are over shooting your target temp then trying to lower it by choking down the fire, causing smoldering heavy white smoke.
I suggest you change your startup process. I would only light about 10-12 coals and then put them in your full unlit basket. Close all the doors and keep the lid on. Open all of the vents, both intake and exhaust and let it sit. It should take less than an hour to get up to temp and TBS. Start restricting in the intake air around 225*-230* little by little till you get to your target temp.
For now you are stuck with choking your current fire, causing heavy white smoke until it gets down to your target temp. Once it is there and can get enough air to maintain itself you should be able to get that TBS you are looking for.
This is exactly what I do. I use the coffee can Minion method. About a 1/4 chimney full of lit lump in the center of the coffee can. I let all the vents wide open till I'm within about 25* of target temp (275*). Then choke back on 2 till about 1/4 open with one all the way open. Top vent is always wide open. I don't usually worry about the temp to much at first, since it always drops when I put the cold meat on. I always wait till it's blowing thin blue or invisible till I put the meat on. It always take 2 or more hours to do this.