<BLOCKQUOTE class="ip-ubbcode-quote"><div class="ip-ubbcode-quote-title">quote:</div><div class="ip-ubbcode-quote-content">I've noticed that in the past myself and even wondered if there could be a programming error. I was told that this was typical of these temperature controls. Good news is, that it will catch up and has little effect on your overall cook. There are some post on this forum about that very topic. </div></BLOCKQUOTE>
My thought is that the Stoker realizes that it went over the 220 value and that turning off the fan was not working. So it thought that by bringing it lower then your set point for some time would even out the end cook.
In this particular cook it looks like you have lots of fuel for the amount of time you are cooking. I think what happened is the stoker started one end of the fire at the start then 15 mins later another portion caught fire perhaps due to a input leak into your cooker. No problem though as the stoker is still monitoring the cook and keeps the fan off. The stoker realizes it's too hot for X period of time and decides to delay applying heat until it the temp goes down by the same amount of time. If you look at the average pit temp over the time you cooked I bet it comes pretty close to your set point.
This is most interesting. I still have yet to log a smoke but I'm all rigged for the next one.
-rob