For some reason my truck has a little lope when idling its hard to tell but you can hear it. I was wandering what would cause this? some people tell me its the FCA fuel control actuator. some people say its injectors. I don't know what to do or believe. Im kinda worried. My truck starts good, no white smoke on start up or when running down the road. i have no codes right now. in the past about a month ago i got the code p0121 but i erased it and it never came back. so i dont know? where should I start?

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I need some input please. im just hoping it not injectors. I dont have no fuel in my oil or no hard starts or no white smoke. ive noticed lately where my connector tubes go there is a little build up of dirt around them maybe leaking a little? and it looks like my headgasket leaks just barely enough to see a faint wet spot dribble down.

 

The FCA is most notable coming to a stop, the idle will vary/waver up and down. Injectors will cause a slight "bump" in the exhaust note, and will sometimes lope when they get bad (most notable with the automatic fast idle).

Right before my injectors failed, I had a fast idle lope that made it sound like a gasser with a radical cam. After having the injectors replaced, I had a slight bump in the exhaust note which was diagnosed as a weak injector solenoid. I also had a cyclic idle coming to a stop which required replacing the FCA.

 

Need some more input probably start by replacing the fca first.

 

Mine does the same thing but only with my trinity on.

 

Which one to change out first? FCA, COV, or rail pressure sensor?

 

What kind if any programmer are you running? It's probably not the injectors or anything internal to the engine. Is the lope more pronounced when it's cold outside and/or the engine is cold? Has your fuel mileage gone down noticeably? The FCA would be a good place to start, sometimes they can be cleaned and work for a while more, then the fuel rail pressure relief valve. If neither of those fix it, it would be a toss up between the TPS and 1 or more bad injectors.

 

yeah the lope is more noticeable when cold but you can still hear it pretty good when warmed up. ill start by taking out my fca and shaking it to see if it moves.

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And its a fast and consistent lope it not a slow lope. a lot of people have told me that is just how alot of the cr cummins sounds.

 

That's how mine sounds and I've replaced the TPS, injectors, and the fuel rail pressure relief valve in the past 3 years. All helped a little but it still has a lope. If your fuel mileage is crap look at the pressure relief valve first.

 

ok.

 

Especially if you're running an Edge box!!! I have an Edge w/attitude and for some reason they, Edge, are harder on the pressure relief valve then other programmers, from what I've heard.