ISX 2250 rough idle at cold temps

[northof60]

Hey guys,

I am working for a customer who has a 2012 KW W900 tri-drive winch truck with the isx 2250 who has had a complaint about a rough idle during cold ambient temps (-30C and colder in northern canada). I dont have a lot of cummins engine experience but have been learning a lot over the past few days trying to figure this one out and from reading this forum.

This unit has been deleted (egr, scr, dpf and vgt) by a local guy who uses {name removed} tunes. From what i have been reading, it sounds like there can be issues with alot of these big name tuners.

The engine runs great in warmer temps, has no codes, smoke, or complaints from the driver other than the rough idle at cold temps, and seems to have full power. When i connect with insite and watch the parameters when the engine is running rough, i can see the rail pressure jumping around about 2500-3000 psi from what the commanded pressure is at. Get it out on the highway and the rail pressures are the same as commanded at about 29000 during a hard pull. Ive checked all the cummins fuel system trouble shooting and dont seem to have any excess fuel system leakage from the rail relief, injectors or pump.

Dont have much tuning experience but im leaning toward the problem on this unit to be a software issue and not a problem with the fuel system or engine itself. Seems to me like it could be stuck in a warm up idle mode or a cold weather mode and causing some erratic fueling due to incorrect ecm tuning.

Any input would be helpful

Thanks

[Rawze]

(01-23-2019 )northof60 Wrote:  ...
a local guy who uses {name removed} tunes
...

If you value your engine at all,.. GET RID OF THAT TOTAL GARBAGE CRAP ENGINE DESTROYING PROGRAMMING ASAP!!!

Welcome to the bad delete club!...
http://rawze.com/forums/showthread.php?t...5#pid13255

[northof60]

Thanks for the reply. From reading the posts from your link, sounds like the best thing to do would be to put the vgt back on and re tune by someone who knows what they are doing.

Saying that, i a dont think my customer would spend the money to put the vgt back on. Is there a way to tune these engines to run properly with an aftermarket turbo? Not looking for any horsepower gains, just a clean running reliable tune.

[Starlight]

Contact Unilevers and have a chat with him about that. He should be able to customize something for you that works. Your customers decision to remove the VGT in the first place wasn't the best move but ignorance still reigns.