Okay so a bit of a update, thought we had narrowed it down to the crank shaft position sensor took a gamble and were fully wrong. So as it sits the truck has a new crank and cam sensor and we have installed a new reg as the one that it came into the shop with had a blow diaphragm and we have had zero luck with rebuilding these. So basically I'm still in the same boat. Is there anyone who has run across this or who works for a cat dealer who can offer some advise other then call the dealer, tried that said they do t know.