Bought an old farm truck from a guy in Missouri. Was supposed to be running when parked. Started out not building rail pressure. Did a bottle test and nothing significant came from that. Replaced the Cp3 with a good used one (took it off a truck personally). I’m able to build rail pressure now but it still won’t start. Did the PPE race valve while i was doing the Cp3 so that’s been ruled out aswell. I tested for voltage and ground at the FICM and that also checks out. Tried starting with FPR and rail pressure sensor unplugged. No change. It’ll start and run on starting fluid (i know it’s bad but almost don’t care at this point). It doesn’t throw any codes, not even low rail pressure. Changed the filter head for another i had aswell as fuel filter. Still nothing. Added an electric fuel pump in just to rule out insignificant amount of fuel. Clueless at this point on it