I think I know what you are talking about. When I start up in the morning If I try to just go right away the car will tend to hesitate as I accelerate. However imediately following that initial take off its fine. I have not had any issues with my car except for that one. I have talked to a few mechanics and it seems that although the thought process is that cars do not need to be "warmed up" anymore you still should not try a hard acceleration until you drive for a few minutes if it is your first crank up in the morning or whatever.