Sharp rattle at idle and stumbles while releasing clutch

[wawazat]

My '03 w/94K on it has developed an intermittent idle problem which when releasing the clutch also causes a severe stumble. Tach does not show a change in RPM, but the idle sound changes to a much sharper rattle. If I am attempting to release the clutch and accelerate when this occurs, the vehicle stumbles and nose dives until I feather the clutch and accelerator and then she takes off.



Engine is bone stock (no chip, box, exhaust, NOTHING other than DCX and Cummins installed)and I just replaced the lift pump (filter mounted) with a new Cummins part as it was on the shelf as I thought that was the problem and I needed the truck the next day. During test drive after I replaced the pump the problem was gone but it reappeared the next day. I change fuel filters every 10K miles. Very little towing or heavy loads, mostly highway miles.



The dealer has it now but the diesel technician is out sick today and won;t be back until tomorrow. Can any of you shed any light on what might be the problem or any search terms that might help me diagnose it?



THANKS TDR!!!



Todd

 

[JHardwick]

Mine has been acting the same for some time, there are a few others here with idle problems too.

 

[rbattelle]

Something's worn out. Jeff - did you check your fuel control actuator?



-Ryan

 

[wawazat]

Coupleof updates.



Dropped the truck off for the dealership to diagnose. You know what came next. Couldn't duplicate problem. Picked it up and for a day it was fine. Today after a couple of hours on the road it happened again. Took it back to the dealership and tech jumped in. Heard the noise, felt the loss of power but after jacking in the analyzer, saw nothing amiss. He called the Super Techs and they are telling him it's the fuel control actuator. New part should be in next week and I'll update you all when it's been installed.



Thanks for your help.



Todd

 

[Hercules130]

where is this fuel control actuator?

 

[rbattelle]

where is this fuel control actuator?

It's the small black cylindrical device with an electrical connector that's attached to the back (firewall) side of the CP-3.



-Ryan

 

[MMeier]

And just how much does this lil' gem cost if not under warranty?

 

[rbattelle]

And just how much does this lil' gem cost if not under warranty?

I *think* it's under $200.



-Ryan

 

[Diesel Power]

if it happens as you release the clutch its your clutch assembly or bearings in your clutch---not your fca, that would cause a rattle every where in the power band, and i mean a bad rattle

 

[JStieger]

I had the same issues... read this



Hope it helps!

 

[wawazat]

Thanks JStieger. The problem has been fixed. FCA did the trick (so far that is). Did a 400 road trip on Friday after picking it up Thursday night and she has been running perfectly. We'll see what happens next...



Thanks for all your help.



Todd