Rich

[RichardTaylor]

I need some help, I have a 2003, 2500 4X4 Automatic which occassionally has a up and down idling issue? Here is how it goes. I start the truck and drive around town stopping and starting as normal and then all of the sudden I start the truck and it begins to surge up and down about a hundred RPM's or so it usually stops after a few blocks or so. Then on other occassions it won't start at all it justs cranks. but that has only happened once. It never seems to occur until the engine is fully warmed up and I have been driving around town a while. This problen does not occre all the time, I can go for several days or a couple of weeks with no issues and then all of the sudden it does it again. I have the new in tank fuel pump as mine failed a few years ago, I change the fuel filter with every oil change and I have about 90,000 miles on the Cummins. I am aware of the injector pump and injector failure issues with this year of truck at this age and mileage but I'm not sure of the proper diagnoses for those issues. I also have an EDGE chip installed which I did pull the jumper on, but did not uninstall yet? What do you think?

 

[Grizzly]

Are you getting any codes? Have you had a trusted, reliable mechanic check it out?

 

[BGlidewell]

does that truck have an FCA?

 

[seafish]

2003 and up CR truck do use the FCA (Fuel Control Actuatator ) attached to the CP3 pump.

The FCA controls fuel volume to the CP3.

Do a search here on FCA and read about it.

https://www.turbodieselregister.com...ns-2003-2007/231076-what-symtoms-bad-fca.html

https://www.turbodieselregister.com/forums/search.php?searchid=1743314

Pretty much diagnosis is confirmed by adding several ounces of two stroke oil to a tank of diesel-- if the roughness or surging goes away, then it IS the FCA.

Pretty inexpensive part compared to other injection system parts.

TCDiesel, a member here, also has good prices on parts and is an top-notch CR diagnostician and is always willing to help TDR members.

 

[RichardTaylor]

Are you getting any codes? Have you had a trusted, reliable mechanic check it out?

No I am not getting any codes and I have not takien the truck to a shop or dealer with this problem.

 

[RichardTaylor]

does that truck have an FCA?

Like I mentioned, my CP3 pump failed under warranty and the dealer replaced it with the in tank pump at around 55,000 miles i think. I dont know if the truck retains the FCA or not when you replace the pumps the way they did.

 

[steved]

Like I mentioned, my CP3 pump failed under warranty and the dealer replaced it with the in tank pump at around 55,000 miles i think. I dont know if the truck retains the FCA or not when you replace the pumps the way they did.

The Fuel Control Actuator (FCA) is part of the CP3 injection pump... if its a common rail, it has a CP3 and FCA. The CP3 injection pump is different from the low pressure lift pump, which was fuel bowl mounted in your 2003 and replaced with your in-tank pump.

As previously noted, your symptoms are that of a bad FCA, which are about $100 from Cummins and take about 15 minutes to replace.

What part of the country do you live?