HI I have the ISX 475 cummins in a 2004 KW, and after having the overhead run, it began to hic-cuo around 1200 rpms. Just a tic, and then building rpms it quits. Under a load or not it does this. Also it does this starting on a (this is where it gets really weird) around 11:30 in the am. if it is sunny out. NO Joke. or if it is foggy out it will do it right away in the am. It puffsa out a big ball of black smoke then clears up.it does this repeatedly every day...but no loss of power, or fuel mileage. Doesnt seem to bother anything but me. no codes or lights on anything. Had it hooked to computer from dealer...shows nothing wrong. I blew a turbo in march so I put new turbo on. and a new CAC. Can anyone please help me figure this out?
e-mail me @
nickelandsons@yahoo.com thanks a lot

 

might be a bad injector.

 

 

I'm kinda leaning on an injector too. I've worked on a few of them isx engines. I think there great engines. Scene a lot of injectors, turbos, and fuel pumps take a dump tho. Sometimes computers don't see everything, so def. Keep close eye on pyro if you got one. Computer should shut it down but ya never know. Had one in the local shop in a w9 k-w that had a head gasket go between 5 and 6... It actually melted block and head. It was a 20,000 ± fix.

 

Updates??

 

Email sent

 

Going to close the thread. Can reopen if he wishes.