Stop with the Kingsford already, I suspect wherever your getting it it is not stored properly and is damp. Switch to lump( burns hotter with less ash) and sart with a bigger fire. From the time I dump the coals on my basket until the meat hits the grate is 20 min average and I run in the 275-350 range. That leaves air, in Cheyenne your around 7000 ft the air is less dense and doesn't support combustion like it does at a lower elevation. I used to have the same problem years ago when I worked the Diamond R up in Sheridan cooking on an ECB. It sounds just the opposite of what is preached but close down on the exhaust a little or go to a larger intake opening to get more air to the fire.
I never met a Cow that I didn't like with a little Salt & Pepper! Certified PORK-A-HOLIC