I have a 2001 5.9 tcd, auto tranny. 51,000mi. Here is the problem as best as I can explain. While going down the road around 45 to 50 mph and tacking around 1600, the rmp jump up about 200 rpm and the engine cuts right out, so I let off on the accelerator and try to speed up again and it cuts out the same as before. It will idle all right, its problematic when moving up in speed. It acts like a tranny slip and shut down. I have a diprical gague to monitor the transfer pump it is working fine. 13 psi. The injector pump and transfer pump were replaced last year. This truck has been babied I dont plow snow or pull excessive loads. I think it might be the tranny but am not sure. Also the fuel filter is new and the fuel is new and I have added winter additives. If anyone has any ideas for me I would appreciate any help Thanks..AUG.:help: :help: -:t -:t