CAT C12 takes 5 to 10 tries to start engine

If check engine liht comes on, pull the codes and reort back. Use the cruise switch to pull codes.
Does it have the primer installed on the seconary housing. Thats the fuel filter mounted to the fuel rail. If it does not, i recommend intalling one. Those block off plates are junk from factory. The prime pump has check vales in it and prevents this issue. Even after you work the air ou of the system, the isue stll happens.

 

check your hpop

 

And What would that have to do with the truck starting and shutting off have to do with that on a cat c12. Just FYI Iam in by know means saying that in a negative way. Im pretty well versed in c12. Just would be a first for me with that being an issue.

 

Does priming it help, with the hand primer?

If yes change your fuel filters and check the o rings coming out. A cut in one will indicate where air is getting in the system. The other spot is check valves, those fail which allows bthe fuel to leave the fuel rail.

 

I was experiencing inability to start Cummins ISX. It randomly choked, after a few seconds of initial start. Once it choked, then I could not start it until after many additional attempts to the point of getting ready to call a tow, and also spraying the air filter with the starting fluid - horrible practice BTW. Finally, I decided to rely on my intuition and replaced both the primer pump and the mechanical pump and it resolved the issue. Maybe I got lucky with the resolution because it could have been an electrical fault too.