That was my theory as well.

 

I've had this happen to me as well. The one thing that I have noticed is that usually if I drive the car for a little bit at say 60%+ TPS and then go and do the first run at 100% TPS it seems to be a little better than just regular warming up the car and going.

YMMV. So like others I usually just do 4 runs, and discard the first.

 

Is this on E85?

 

I see it for pump gas and E85.