Unsteady Idle

[RustyJC]

3rd genners, can you help a pore ole 2nd genner out? An RVing buddy of mine with a 2003 HO/48RE 3500 DRW e-mailed me with the following problem, and I'm not familiar enough with the HPCR Cummins to help him out. Can you point me in the right direction?

At idle my truck drops down to about 500 rpm and then shakes like it does when you kill the engine, and promptly jumps back up to 1000 rpm and goes back down to normal idle. It has also started doing this while in gear. It started this a week ago today. I took it to the dealer Wednesday and it did it once while they looking at it, but it has not set any codes in the computer. It has gotten worse since then. Any ideas on what it might be?

Thanks for your help!



Rusty

 

[RustyJC]

Hmmm... ... 61 views and no replies. I guess this must not be a common problem. Just my luck!



Rusty

 

[XcumminsX]

it is a common problem... Maybe not to 500 rpm mine durges about 100 rpm with at high idle. Do a search youll find some info on it, many people have this problem.



Nick

 

[JWTX]

Sounds very suspicously like what I had. Look at my threads.



https://www.turbodieselregister.com/forums/showthread.php?threadid=79598&highlight=truck



and the solution



https://www.turbodieselregister.com/forums/showthread.php?threadid=90883&highlight=truck

 

[RustyJC]

JWTX,



Thanks - I passed that info on to Jerry. It certainly sounds suspiciously similar.



Rusty

 

[DCTECH]

HAD A 2003 HO 48 RE DOING SAME THING IF IT STAYED RUNNING. TRANSFER PUMP WAS OUT, STILL DID IT AFTER REPLACEMENT. REPLACED HIGH PRESSURE CP3 PUMP AND OK NOW. HAD 12,000

MILES ON

 

[RustyJC]

Thanks, DCTECH - that's 2 for the HP fuel pump.



Rusty

 

[CLAYTON]

Originally posted by DCTECH

HAD A 2003 HO 48 RE DOING SAME THING IF IT STAYED RUNNING. TRANSFER PUMP WAS OUT, STILL DID IT AFTER REPLACEMENT. REPLACED HIGH PRESSURE CP3 PUMP AND OK NOW. HAD 12,000

MILES ON

Did it just happen one day or did it build up to the point were you had to have it replaced? Did you get a different pump or get it replaced under warrenty?