Alright so I'll type the whole story I bought this 96 Cummins in a state of disorder from a co worker. It was a one owner truck with 261k on it. 5speed truck. Besides that the truck ran very rough would sputter and smoke under throttle and only idled at 400 rpm. Consensus was check the fuel pressure. I buried a 30 psi gauge after I cleaned the ofv. So fuel psi wasn't the issue. Changed the fuel filter . Still nothing changed.

So I bit the bullet and bought 5x12 injectors and a Seal kit these are 155 so I used the thin washers. I changed the injectors out and primed it the truck runs now and no sputter under rev. But im getting constant air out of #3 delivery valve. It just sprays, so it is pumping but air mainly. Every other cyl has fuel at it. I'm a little confused by this I work on diesels all the time as its my job . I've never seen air be in only one cylinder so I almost have no clue what it could be any help is appreciated by the way thank you for welcoming me to the site

 

check the fuel line and the delivery valve closley, one is either cracked or not seated correctly .... did you use a torque wrench or just till it was thight ? never a good idea .........

 

I've been suspecting a dv as the problem but everyone I talk to says they've never heard of one cracking. The injection lines would leak if they were cracked. And being a mechanic yes I used a torque wrench

 

Good deal on the TW.. I would go after the dv as well..

Might try freash filters and when u fill them use straight dex atf , might dislodge what ever is gumming up the pump, and some lube couldn't hurt either