08 Cummins ISX CM871 After Run

Mike Johnson

New Member
This motor (2008 with stage 1 PDI delete in a 09 Prostar) started after running a few weeks back. It runs for 5-8 seconds after shutdown as well as running really rough in the idle kick-up mode (a few seconds after start-up when the idle kicks up to the 800 rmp range and continues running rough till it "warms up" (60 to 120 seconds). My mechanic couldn't get insight to pull any codes and thought it was an injector, so I had all six rebuilt. same issues. replaced the stop solenoid, same issues. Took it back to the PDI shop that did the delete, they also could not find any codes but assured me it wasn't the ECM. They indicated it was likely one (or more) of the fuel actuators and explained the expensive process of testing them. Thought I would post here before coughing up a couple more thousand dollars for opinions of the diagnosis. also, if I drive the truck with the after run problem (runs great going down the road), how badly could I damage the motor? Thanks for everyone's help
 

mndriver

curmudgeon extraordinare
Supporter
I'd start with resetting the computer back to stock. Especially after it didn't start till pdi got into it.
 

Mike Johnson

New Member
It's been a year and 3 months since PDI did their thing....................I not buying another DPF and VGT turbo. The shop did install a pre-delete ECM, had all the codes but did the same thing. That's how they determined it wasn't the programming. Thanks for the help.............................
 
Last edited:

mndriver

curmudgeon extraordinare
Supporter
I was under the impression that this was a recent switch over.

If it's a new issue and some time between the conversion, then something else is the matter. And I don't know enough about the ISX to make those suggestions. I run a Series 60. So if they are suggesting diagnosing the actuators, I'd follow their lead.
 

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