Originally Posted by oldbill
If your dampers are almost closed and the temp is rising I'd say that your fire is too big. The problem there is that choking down on the intake damper too much will cause dirty smoke and creosote which means bitterness on the meat. Start with a small fire with maybe a half chimney of charcoal and a split or two depending on how large your pit is and let the wood burn until you can see that there is little smoke being produced indicating that the wood has fully combusted, the goal is to get an established bed of coals going and less smoldering wood. It's a lot easier to add fuel to a fire than it is to take fuel away after the fire gets too big. You should be able to keep your exhaust damper completely open and control the heat using only your intake damper. If you already have a fire going and you have to use both dampers to control the heat then open everything up and let the fire burn down for a while before putting on the meat or remove some of the fuel if possible.
I just realized that I misread your question! For some reason I read that both the intake AND exhaust were nearly closed . Sorry for the long winded response!