#3 cylinder misfire issue...Cummins ISX CM2250

With the same injector, you could have a harness issue between the ECM and head pass though connector. Or, internal ECM problem with that injector driver.

 

I agree,

Based on the symptoms it seems it only acts up after long runs or when hot. This would definitely point toward ECM failure vs wiring issue . Wiring should be more consistent and not so much temperature related.

 

3m dust remover can be used to cool down hot items quickly. If you turn the can upside down it gives off super cold vapor. If you try this,start with a harness plug away from the ecm to get a feel for how long to spray,distance etc. I think your ecm is in a aluminum case so a quick cool down in one spot could crack the case.

 

Willing to bet it's your Jake solenoids. If it's still acting up take off your valve cover and see if the Jake's are actuating when they shouldn't be. If they are then replace the solenoids.

 

I don't know if the jacobs want to interfere with the engine. When she is working I hear bells in there from the valves. And that is such a sound to me that she will take anything vertically downgrade.

But for tired smokey joes we like to find a stretch of highway reach temp and put the foot on the floor. Run the hell out of that engine to clear the soot. Once that's gone everything else is possible.

 

The problem I had was intermittently the truck would only run on 3 cylinders. Had no power and was sending a lot of unburned fuel thru the turbo. Then all of a sudden it would stop running like crap and would run great until the next time it decided to act up. Found out from Jerry mckneely out of Griffin,GA that he had test drove a truck that was doing the exact same thing mine was. He bet me 1k that the Jake solenoids were the problem. I'm glad I didn't take the bet lol

 

So the Jake Solenoids were the problem

 

Yes