2008 6.4 Help Needed

[a4t1rat]

I have a 2008 f450 it has been dpf deleted and egr deleted. Its running a H&S xrt pro. it has had intermittent starting problems. and now has developed stalling problems. It has beed to the dealer 3 times and the have said there is nothing wrong. It has no codes and runs perfect after you get it started. I live in Utah at 5000 ft. today I went to start it and it wouldnt start but after about 10 tries it started, tried to drive it made it about 1/2 mile and it quit and didnt want to start. finly got it running and quit again.. still no codes ?? when it quits it is like you just shut of the key. And when you try to start it it will turn over but no fire, any ideas would be helpful as I am about to ... well never mind. I dont think it is PATS problem that has been fixed. On a side note I now the truck has a new motor so maybe loose connection? truck has 90k on it now.

[superduty6.4]

When was the last time the fuel filter were changed?

[a4t1rat]

I thought of the filters too so I changed them .. they were changed by ford last time it was in ... ya right , the top one was new but the PITA frame mounted one was not new. So we will see if this helps I dont think it was that bad but we will see. any more thoughts would be helpfull.