Engine Surging

[SRossi]

Ive got an 03 with 157k miles on it. It surges mildly almost all the time, and sometimes will surge real bad and die. I replaced the lift pump with a Carter and Vulcan RLK. When the surging is mild, the rail pressure will be anywhere from 3500-6500psi. When its real bad, the rail pressure will drop to 2200psi. .

The truck is not throwing any codes. The problem got a little bettwer after the relocation of the lift pump, but still does it. Do I have a bad CP3, or something else I should look at?

 

[SRossi]

I just replaced the check valve on the rail, and the engine does not die any more. It still surges, but does not drop RPMs. My rail pressure is fluctuating between 3500psi and 9000psi. .

Any ideas?

 

[sag2]

If it can't hold rail pressure and it has enough flow in, most likely you have a bad FCA, or contaminated FCA from water or debris.

 

[SRossi]

Fca ? ? ? ? ?

 

[SRossi]

to the top

 

[RMalone]

Sounds like a FCA to me also (flow control accuator), it sits right on the cp3 and is the part the ecm wires connect to, it's to the rear of the truck on the cp3. DO NOT get one at the Dodge dealer they wanted close to $200 when I bought one and then I got it for $90 at Cummins. It is very easy to change.

 

[SRossi]

Yup, turned out to be the FCA, thanks for the help fellas!

 

[Prairie Dog]

Chock up another one for SAG (you too RMalone)!