Engine/Transmission (1998.5 - 2002) 1999 24 valve ruff idle

[Cumminspwr2500]

hey everybody i have a 1999 cummins 24 valve with 130,000 on it. i have 100hp injectors and a airdog sysytem. When the truck is warm it idels ruff it stays about the same rpm and my feul pressure guage stayes at 11 to 12. No codes are thrown and when i put it in gear it runs fine. can anybody pin point the problem? is it lift pump or injector pump or something else? thanks

 

[JLandry]

Just to clarify: You're saying it has a rough idle only when warm and then only in neutral?



Did this happen suddenly or gradually over time?



How many miles on the injectors and the fuel injection pump?



Are there any other modifications or power enhancements (programmer, etc. )?



Regards,



John L.

 

[Joe Mc]

Agree w/JLandry = need more data. What part of the country are you in, have any other mods been done, has the fuel filter been changed recently or last time it was changed was ? ? ? and did you recently fuel up ? ? ? Create a signature so we can help and as time goes forward others will have a better idea of what's what with your truck out of the hole and be better to quickly help you.



at 130k miles do you know if the valve lash has been done yet? Just a question, shouldn't make a difference in idle if it wasn't, however, if it was and they're not correctly set . . .

 

[Cumminspwr2500]

yea, the idle is ruff when its warm and in neutral or the clutch pushed in, in gear. it happened suddenly and since then does it every time when warm. the truck came with the 100 hp injectors and the airdog system. but since i have owned it ive put about 9,000 on them. i do not have a chip or programmer, just injectors, air dog system, clutch. i live in upstate NY on the border of canada. I just changed the two air dog filters a couple months ago. no i have not done the valve lash Thanks for the help

 

[DougMillsJR]

I had a 98 24v with 150000 it idled rough after running awhile. I replaced the stock injectors with 7575 horse edge hammers and it smoothed out the idling. Have 2000you with same problem just haven't worked on it yet.