I just picked up this truck a couple days ago and went through the break in. On our first run with it today, the truck seems to stutter, or hesitate a bit. We tried tuning the engine, but it didn't help at all. If I stomp on it, it doesn't do it all the time, but if I gradually increase power it does it. Could this been a problem in the tranny or the third gear problem I have read about? Or is this a tuning issue? Thanks!