Cummins n14 injector issue

Pressure gauge installed. Pressure is solid during entire range of operation. Ran truck from a bucket of fuel looking for any air bubbles on the return line or performance changes. All stays the same, slight miss. Now I'm getting insite messages that the "ecm detects conditions in which the cylinder cut out test should not be run"
It's looking like ecm related. Not sure what else to test/check

 

What was your range of fuel pressure?

 

Appx

127psi at idle and more than that depending on accelerator position appx 145psi at 1300rpm I think it was. Pressure was rock solid at steady rpm. I was hoping to see in bounce around during the miss but it never did.

 

Did some more testing with insite and a fuel pressure gauge.
Fuel pressure bouncing from 120 psi to 130psi at 900rpm pto speed

Appx 135 +- 2psi @ 1091rpm

126psi at idle +-1psi
Initiate cylinder cutout test
135psi +-3psi rough idle no #4 injector response

Accelerator based cut out all cylinders 85-89 rpm difference EXCEPT #4 at only 11RPM difference.

125psi @ idle after test slight miss no smoke unplug #4 injector and she stumbles

 

As a follow up I ended up sending the ecm off for testing to DSO Industrial. Exceptional service and very fast. Injector drivers in the ecm was my problem. I have all the tech manuals for this engine as well as cummins insite. It is kind of difficult because of the possibility of bad reman injectors. You can waste a lot of time and money playing swap the injector. I even hooked my injectors up to an oscilloscope to watch the waveform and they all looked good. I guess the timing from the drivers was just off a bit. There was also a ticking in the overhead that I could never get to stop no matter what I tried. That has also gone away with the new ecm.

 

Thank you for following up and letting us know what you found.