Try experimenting with other lump. The KJ charcoal is, in reality, Wicked Good. Although a good lump, I kind of prefer the Lazari oak for the last few years. I get larger pieces and not so much fines in the bottom. When I note a drop in long cooks I also use the ash tool and give a couple pokes to the grate from the draft door, usually works just fine. Then again when doing a long cook, I make sure and really clean it out beforehand.
PNWBA - Hayden, Idaho http://www.facebook.com/BC2BBQ