I know what you are saying is true having resurrected several vehicles through the years. The question is why would it have to run for 10 minutes for that to become an issue? Could leaky injector seals be an issue but would that show up at cold start time and improve with heat? Can the fuel accumulator cause the issue? If we equate time running with engine temperature, what opens or closes or starts or stops with engine temperature? I am sure the answer is simple and logical, I just lack the skills and abilities in this area to see the logic.