cummins isx problem

Check your coolant level and report back if it's low and how much.

 

he didn't say what year motor? Good call on coolant level. Someone told me they (2008 and above) are very sensitive to coolant usage.

 

Sounds like an injector starting to go out. Did you get the check engine light on ?

 

ISX's are very finicky about fuel filters. There are two of them. I had this happen with an ISX that started blowing white smoke and acting up before and the primary filter needed changed. No codes. It seems to happen all of a sudden, like yours, without warning. At least it would be a cheap try to change a fuel filter and see if that solves the issue.

 

id start with seeing what the code was first, you could try changing fuel filters but isx has a fule pressure sensor that with set active fault codes if the fuel pressure ets to low, it might have set a "951" fault code for cyclinder imbalance which could mean a number of things, but untill you know for sure what code was set active everthing
i've said is my opion.