I literally just joined this site to reply to your thread (okay thats not the only reason
I got my truck almost a year ago now, and up until a few months ago it was RIDICULOUSLY gutless and had no power. It was getting really frustrating and annoying.
I know this might not be the case for every situation...but what I found when changing the timing belt and water pump was that the belt was literally off by about 10%. The belt was pretty much fine but I changed it anyway..Upon actually having it put on the RIGHT way it has so much more power and "go". It was literally like I got a whole new truck, it was that big of a difference.
It really gets it now and I am very happy that it was just a small thing like that. I was starting to get frustrated that I just had a gutless truck.