May have figured out my RPM issue.
First a recap, after an oil change the shutoff solenoid started acting up then I couldn't get the truck over 1000 RPM...how any of this is related is anybody's guess...the diesel Gods are restless.
First I tore apart the fuel system, replaced the filter and the housing, addressing some casting issues I had patched up in the old one, but no joy on the RPM issue. Then I rebuilt the shutoff valve making it a full manual, again no solution finally I addressed the Pressure Time Filter in the pump itself. I tried every tool I could find to get that thing out even built a dam around the plug with 90 minute gasket goo and soaked it in Superzilla penetrating oil for a week. Was about to ask your learned opinions on this august forum when I realized I hadn't tried my gardening tools yet. Go figure a hand held Mattock did the trick. The filter appear to be clogged with sludge, fortunately I don't see any metal on the magnet. Have a new filter on order from Mike's, will keep you informed.