Hi, I just bought a 03 f250 6.0 with 180k, it ran for 2k miles great, then lost power and died. Towed it to my shop, it restarted but chugged @ idle blew black sooty smoke and had no throttle till it warmed up but then if I hold it at wot it would only rev to 2k rpm. Today now it wont even start. I changed both fuel filters and the lift pump is working any ideas would be helpful. I am thing about replacing the IPR but would like some input before I waste my time. Thank you.