So i got stranded today and ended up towing the truck to a diesel place. They ran buzz tests and swapped out glow plugs blah blah. turns out it was a relay to the electric furl pump kit on my 97 350. The truck had a sudden and severe lack of power and was stalling out right as i was getting on the interstate.
So after all that about half way home on long distance i start to notice an occasional white puff. my truck normally dose a lot of black and grey. But as i kept driving it got worse and more frequent. the truck would instantly drop 300rpm and puff and jerk while i was in the middle of nowhere i was not gonna stop. after a while it calmed down but its still happening.
I know they replaced the driver side wiring harness re-did some of the plug line and replaced the crank sensor because the truck would occasionally die when slowing down from 70mph. The truck died again as i pulled into my driveway. I have not looked into it yet but dose anyone have any ideas on whats going on?

Perhaps they replaced the cam sensor. There is no crank sensor.

Could be any number of things. Without obtaining codes, doing diagnostic tests, and/or reading live data, you're guessing. How's the oil level, and how old is the oil?

Tell us more about your e-fuel setup as well. Does it have any provision for measuring pressure?

its actually a little over full but oil has like 1000 miles. The truck was not having this issue before they worked on it. As for the e fuel i dont know much about it it just looks like its pretty basic pump is always running and its just an inline right under the drivers seat.

So what led to you getting stranded?

In the end it was the fuel pump relay. It behaved different from the first time it happened so i did not think of it until i realized i could not hear the pump.

no not sure why it dose it. However it goes away after a couple weeks and it comes back any time i use a scan tool to erase the fault codes.