Cummins n14 injector issue

Have an n14 celect plus. Slight random miss at idle. #4 injector failed injector cut out test ( no change to engine operation when #4 shut down. Swapped #3 with #4 injector. Problem still in # 4 hole.

Truck definitely idles a lot smoother before I open insite. Once I hit the start button without selecting any particular injector it has a bit rougher idle but it doesn't seem to miss.

New pistons and sleeves last year. New cam shaft this week. New cam followers this week.

Ready to send ecm out for testing unless there is something else I'm missing.

Replaced all Injectors last year with remans chasing this problem... still chasing

 

Did you check the all of the injector wiring? From injector to ECM?

 

Just look at it or am I checking voltages or what?

 

I'd start with a visual check for obvious damage. Definitely check the pass-through connectors. The seals can break down and oil can get into the wiring. If that checks out I'd check continuity from ECM to the problem injector.

 

Would you consider #4 the problem injector or does the computer do some sort of goofy balancing act and the actual problem could be an over fueling injector somewhere else? Would it be wise to swap 1&2 then 5&6 to see if anything changes or is that chasing unicorns?

 

I'd say if the problem stayed in #4 even after swapping the injector that the issue is likely related to the #4 cylinder and not the injector.

 

Ok. I'll check the harness and pass thru.

 

Mine would do same smooth out on insite, per Wore out I started adding 1 gal 2 cyl oil to 100/150 fuel idles like a dream .

 

It’s a little late now. But if you ever do buy new injectors, make sure to get the PX remans and not the RX remans. The PX has a way better rebuild quality and aren’t prone to failure like some of the RX remans

 

I'm guessing that's the part # you are referring to.