I load the egg with lump, breaking any big pieces down to baseball size. I start a full chimney of lump and let burn down to half. Pour the hot lump in one spot, usually the back right corner. Do not spread it out or you will overfire. I let it get going for about 10 minutes and then close down the bottom vent to about 1/4" from totally closed. The daisey wheel is positioned just barley open about 1/8". I can run for many hours, 12 to 16, on a full load of lump.
I cook on 3 different LBGE and they all run slightly different so you will have to practice to find out what works for you.
If you continue to have issues buy a guru and that will solve your problem.
Grate temp will be between 50 and 75 degrees lower than dome temp from my experience.
Hope this helps.