2004 F-350 6.0 super duty starts when it feels like

just bought a truck a week ago, drove it for a day, and then wouldnt start the next morning. tested the voltage everywhere and everything was pointing to the IPR sensor. it wasnt pushing out any smoke at all, crank no start. after the dealer came and towed it, it started right up when they got it back. it took two days for it to act up and not start for them. prior to purchasing they replaced the batteries, starter, battery cables, and glow plugs. they tested the cam sensors and found they were working fine. a friend of ours has the identical vehicle to ours except a dually, and his truck was doing the same thing and it was the IPR sensor. truck wouldnt start, then an hour later it would start. the truck has been in the shop for 6 days! we suggested the IPR sensor to the mechanic at the dealer and he shrugged it off and said those RARELY ever go bad. i have just about had it with these mechanics. can anyone tell me what it could be, or do you think it is also the IPR sensor?

I don't know about that but IPR's do go bad... more often than they should. It's not gonna show a code for it because it's not a sensor. If he cant find a code tell him to disconnect the ICP sensor and see if it starts. If it starts and runs its the ICP. They dont always set a code when they go bad. But once you do disconnect it it'll set a 2285 code so ignore it in your diagnosis.

thanks, but already tried that and it still didnt start...

the ipr can be check with a pressure guage or a tech with the proper reader but a common probles with the 6.0 and 7.3 is injector control moduel the ipr along with the icp control oil pressure to the injectors did you have any troubles like dropping a injector when driveing

the injector control module is good. dont have access to any fittings to test the IPR that way. when the truck does start, it runs perfect. they dealer hooked it up to the tester and said it came back with nothing. it has been a week now, and it has not started in the morning 3 out of the 6 days they have had it(excluding sunday). every time it does not start they test everything, and then they leave it for an hour, and they will try it again and it starts. only thing i can personally think of is the IPR valve is getting stuck. i have been reading up on other forums and calling mechanics at other shops to try and see if they can come up with anything else and they all say the same thing. i dont know if they just dont want to change it because that part through ford is over $500 and they just dont want to stick more money into it, or because they dont want to realize that a back yard mechanic knew what was the problem when they picked it up a week ago.