Well, don't know what to do now. I took advice here, nothing helped. So went to a local diesel mechanic and he took a look and refused to work on it. Told me to take it home and clean off the sticky egg yolk, salt and pepper and bacon wrap (that was my idea).
Actually I have a friend who is a diesel mechanic. I'm going to try to work on a couple of your ideas and can call on him for guidance if I need it. If that doesn't work I'll have to wait until he can get to it.
I have run an edge Superchips tuner for several years. It has two settings, one for economy and one for maximum towing when I'm pulling my camper.
Thanks again for your help.