The engine going to 2200 right off the bat sounds like normal operation of a stock 47rh
. Everybody is suggesting get a new trans and transfer case when the truck IS moving and IS shifting. Since the add said that they replaced fuel system parts, I would start there, get a fuel pressure guage on it and see what's up. Inspect fuel lines for dampness and change filter. I would be ****** if I bought a new trans and new T-case when all it needed is some fuel supply and some lube on the t-case linkage. :{ . The transfer case is letting the truck move and is not making any bad noises, right? So it is not the first problem. Pull the trans pan and inspect for glitter, the fluid should be a nice red but I have seen it pretty brown and the trans still works fine. If the trans is shifting and there are no metal shaving in the pan I would move to power from the engine as being the problem.
