just called the local diesel shop and he said he sees a lot of these trucks with the same symptoms. he said i could try some stanadyne product he sells and that i would be surprised at how many times it works for these symptoms. i think mine is beyond that point though. he said he could overhaul it and bench tune it for $600 plus labor if he takes it off and puts it on and bumps the timing up. does this sound reasonable? given the fact that i have already done all the small things that could be a problem and my fuel pressure is good he feels sure its the pump and he named off several things he has seen happen before to cause this. just don't know if i want to spend $1000 on and old truck and still have a problem if thats not it.