I have a 2001 2500 Cummins 5 speed. It idles at 800/850 which is much too fast for the 5 speed, I have to keep slipping the clutch to slow the truck down in parking lots, going around turns, etc. If I don't pay attention it can become dangerous. Nowhere in my huge service manual does it say what it should idle at, or how to reduce the idle speed. I need to get it down to at the most 700 rpm. I haven't been able to find out if you can slow it mechanically or it"s done on the computer. And I need to know if lowering the idle speed will cause any thing to go wacky.

Thanks
John

 

Idle speed is set in the computer by Cummins. You would have to take it to Cummins and turn the idle speed down. They are the only one that will have the software to do it and it will cost you a good amount of money. Unless the programmers have something I'm not sure about that.
As far as it running wacky in the winter it will idle ruff or lope bad or worse then it does now when its cold out

 

Thanks Pizzo, I'll try that, there is a Cummins dealer locally, never thought of them, I kept thinking Dodge, and I don't ever remember getting any good advice from a dealer.
John

 

you have to ask them first I am not sure that they are able to do anything Insite works on j pin connection where your dodge works on OBD11 port
I kinda upgraded my truck to accept both witch is just running some wires and tapping to the back of that OBD11 port just so i can hook in INSITE. Since Insite is a tell all program. But its worth a shot and may cost a little money to adjust the idle for you. plus the motor is supposed to idle at 750-850rpm it also should say that on the serial tag drivers side of motor on the valve cover

 

Prizzo
I haven't had chance to get to the Cummins dealer, I've been out of the state for a while with no computer. Anyway, this INSITE port, I assume it's a pigtail on the OBD wireing. Is this a kit I can buy or did you just sort buy the connector and wire it in. I know that the engine is supposed to idle 750/850 but as I said in close quarters and in traffic its just a constant slip the clutch to maintain a slow speed which isn't real good for the throwout bearing. I just redid the clutch on the truck and I didn't have fun, it sure wasn't as easy as my old Chevy, and I've got no desire to crawl under that thing and do it again any time soon. I do have a friend that has the same truck but 2002 and his idles at 700 with no problems.
Any advice would be greatly appreciated.
Thanks
JAH1

 

yeah dude i wired mine in just for me to plug my laptop at work in cause my mentor breaks and i cant read the codes on it but for you you will need a wiring diagram and the right ends to plug it in to on the side of the block and i just had a one laying around its that needed to be replaced on a forklift and all i did was tap into the wires for the obd port they are the same for you if you could get that plug for free and had the diagrams then i would say go ahead and do it but the only people that will use it is at the cummins dealer and they have the obdII ports as where my work DON't have them so it will be useless for you
i should look and see if i can adjust the idle on my truck I will see if you can in the morning with it i know its set via the computer but you have to have the CUMMINS DEALER insite but what your explaining is really nothing wrong with thee truck your just having trouble in traffic and you wanna stay in 1st and coast through

 

Again, thanks for the info. I am weak on wireing but I'm pretty good mechanic with the older Chevy gas engines, and I am familiar with diesels but not this Cummins, I did work on diesels in the service but it was the old Detroit 71 series. So any help I can get I would greatly appreciate it.
John