Need N-14 Help

We have a 95 N14 celect it has always sounded rough at idle the heads were replaced beacuse of water leaks water tubes between hd's. Even with different hd's still sounds same,This unit runs every day maybe there's a way to short out the injectors ?, checking temps on the manifold I try to do it when first started cold. If there's a weak cyl it might miss cold then fire after warmed up,we had a older detroit that had a bent rod from water in the cyl that would miss cold then warmed up would be ok, when torn down at a later date the rod was discovered.

 

You are correct that a mechanical malfunction with an injector will not initiate a code or check engine light. If you are thinking an injector is the problem then the best thing to do would be a cylender cut out test and see how each one is performing.

 

sounds nuts but... try removing the belts from the alt and see what happens I had one that would only miss at 1450 the alt was seizing. Had one once that would miss at an idle on say #4 so you could unplug the #4 injector no change. unplug #6 also then plug #4 back in and it would pick up #4 till you plug #6 back in #4 would drop out again. move #4 injector to any cyl and the problem would follow the injector. replace the injector and the problem would move to another cyl say #2. put the old #4 injector back in, in any other cyl and the miss would stay with #2. put a set of reman injectors the truck ran fine for about 15 min and the whole process would start over. tried 6 sets of injectors 3 ecm's injector passthru and injector harness. had an engineer from cummins come out he put a set of injectors in same thing. cleaned the grounds check fuel psi check for air in fuel the engineer finally admitted they did not know how to fix it but they did know of 1 other truck doing the same thing.