I have a 1997 Dodge diesel pick up 4x4 that I just purchased and runs great until I started pulling my boat into a 30mph head wind and noticed that at half pedal this thing started losing power and i could regain if I let off and kept the RPM's under 2000. I really started paying attention to it and even without a load it seems that the truck at anything greater than half pedal starts stalling a little. The truck has 118K miles on it. Any help would be appreciated... It either has to be a fuel related problem or a turbo issue. One note though is that the previous owner stated that he had a diesel shop turn up the pump on it. I don't know if that will effect it or not. (PS my boat only weighs 3000lbs overall and the differential's are 4:11's so I know this thing ought to pull the boat inside out.

 

First thing to do is change the fuel filter. If that doesn't cure it the overflow valve on the pump may be bad, that's the next cheapest/easiest thing after the filter.