Yes, on a glow plug engine you can remove the glow plug and unplug the injector and see if the injector is leaking. You cannot do this on a newer Cummins 6.7 because they use a grid heater instead of glow plugs. If injectors are leaking that badly and the harness and ECM are ok and the pressure sensors are doing their job, just replace them. I'd be suspect of contamination in the fuel system as well if you're seeing repeat failures like that. What specific engine models are you seeing this on?
Also keep in mind that injectors on certain models have to be programmed so that the flow rates are correct. I believe Ford calls them an IQR code or something like that. Duramax does the same thing. You probably already know this, but figured I'd throw it out just in case.
Last edit: 3 years 2 months ago by thatmechanicguy. Reason: More info for topic
Hope these can help. These are from the Cummins factory training classes on the ISB6.7, which is basically the same engine that is put in the Ram trucks with a few minor differences. Let me know if the attachments do not work. The TSB for advanced engine troubleshooting is going to be what you were primarily asking. Data PID's for specific issues. It is LONG so take your time reading it. Keep in mind that all of this info pertains to Cummins Insite factory scan tool so you'll still have to interpret things a certain way to find what you're looking for on an aftermarket scanner, or light duty scanner. Basically the TSB has you look at the PID for "user fueling state" to determine a path to go in diagnostics for a performance or running concern. If the scanner you use doesn't have a PID like that then it may or may not be helpful, but its still a plethora of info that you'll get something out of.
I also have tons of information on Allison transmissions if that is something you are servicing or diagnosing a lot. A lot of the files I have are over the capacity limit for the forum so I'd have to email them to you if that's something you'd like in the future.
