yeah, i was just mainly thinking disconnect the controller (plug back in as it came from the factory) to see if it will idle (assuming it was easy to take out of the loop). If it idles then you've found the culprit, if not you've ruled something out. Really sounds like a quirky computer problem, have the same issue with my truck sometimes (check engine light), the battery disconnect issue fixes it everytime.
Dont necessarily think it would be the valves out of adjustment, but easy enough to rule out as well you havent adjusted them yet...