Intermittent Cutting out
#1
#2
TPS (throttle position sensor) is the next thing I would check out. They have a "failsafe" in the design to fail at the 0% position rather than 100%. They can be checked with a meter, and iirc reset with a little process, lmk if you want me to get into a manual for you, if not then I won't waste time doing so!
#3
make sure your filters are good. when the fan clutch wires get chafed, cut, broken, etc, it will make the truck run funny. grounds and battery terminal clamps that need to be cleaned and/or tightened will also cause the truck run funny. what is the rail pressure when this happens? could be a fuel issue.
#4
#7