2017 2500 6.4 intermittent no start

[mitch42]

I have a 2017 ram 2500 6.4 that at times it will not start or runs very rough if does. If it does not start it will just spin over until I turn the key back then it will start right up. A few times it would start and act like it was running on 4 cylinders and I can shut if off and restart and it will run fine. It usually will do it after I have been driving it and then let it sit 20 or 30 minutes and try to start it and it will act up. It does not do this all the time, it might run perfect for a few weeks then do this out of the blue.Also the check engine light never comes on and it has never set a code. I thought it could be the tipum so I ordered one of those and swapped it out and the next day it did the same thing. Anyone ever ran across this.
Thanks

 

[Gordo2212]

The rough starts almost sounds like battery but I don’t think that would cause the engine to run rough after starting though.

 

[mitch42]

It has been doing it for the past year with the same battery. It spins over fine even when it does not start. I might not be able to get it to act up for a few weeks. Just worried that one day it is going to leave me stranded and that might be what it takes to figure out the problem
Thanks

 

[mitch42]

I just got it to hard start today and I have a fuel pressure gauge hooked up to it and when I went to start it the fuel pressure did not climb all the way up like it does when it starts right. Also when I shut the the truck off the fuel pressure drop slowly back to zero ( 20-30 seconds ) anyone know if it should hold the pressure and if so how long
Thanks