'07 cold start & idle problems-bad fuel, fca, or other ideas???

[EArp]

Ok it was only 60 degrees here in Austin this morning and when I started the truck it idled very rough and almost died. I had to give it a little throttle to smooth it out. After this, I also noticed that at a stop light the idle will vibrate my truck slightly. It has done this all day long. At highway speeds it runs great. Very smooth with plenty of power. No smoke either. I'm suspecting either bad fuel or the FCA. I just filled up earlier this week and also added some Diesel Kleen (power service) to the tank when I did. The tank is still nearly full. The truck only has 40k on it and I change my fuel filter regularly, so i'm not as worried that it's an injector. In addition, I don't run a pressure box or anything to bump up the rail pressure. My truck also bucks a little bit when going downhill on cruise control, and from what i've read from you guys it seems this too is a symptom of a faulty FCA. What do ya'll think?

 

[GCP]

I'm experiencing the same symptoms. Anyone have suggestions?



Thanks,

GCP

 

[EArp]

It's so weird because the truck is back to normal now??? I guess it could have been a little trash working it's way through the fuel system, or maybe I just had some bad fuel. I did really "blow the soot out of it" though several times while I was having the symptoms, so maybe that cleared out whatever was causing the problem. From what i've also read from other posts, it could have been too that the FCA valve was temporarily "stuck" or something.

 

[cerberusiam]

Start by adding 2 stroke oil to your fuel. See if that will make a difference. I typically run a mix of Power Service and 2 stroke oil or 10 wt non-detergent as an additive. Zero problems with 135k.

 

[bwall7116]

It sounds like a sticking FCA but keep an eye on your oil level. If it is an injector it will dump fuel into the crank case and thin the oil. Not likely in your case but you hate to have it happen and screw up your bearings. My truck started running a little rough at start up and idle until I added 2 cycle oil. Now the truck runs smooth and quiet, no more ticking from the high pressure pump.

 

[EArp]

What kind/brand of two stroke oil are ya'll using?

 

[HBarlow]

... ... ... ... ... ... ... ..... My truck also bucks a little bit when going downhill on cruise control, and from what i've read from you guys it seems this too is a symptom of a faulty FCA. What do ya'll think?

I hope you don't replace parts trying to cure the bucking that occurs on all Dodge-Cummins trucks when using the cruise control on a gentle downgrade.

All three of my Dodge Rams have done it occasionally. It happens as the cruise control attempts to maintain set speed on the downgrade and shifts back and forth from fueling to no fuel condition.

It's perfectly normal. Maybe the engineers didn't quite get the software perfect.

 

[AWise]

What kind/brand of two stroke oil are ya'll using?

I use the Wal-Mart SuperTech 2-stroke oil... . just make sure it is TC-W3 oil. It is sometimes referred to as an "ashless" oil and it burns cleaner.

 

[Flyfishing]

The mechanic at Duncan auto said that a bad FCA will cause the engine to "hunt" at idle... See thread "shakes your fillings out"



Richard

 

[wcjp]

BTT



Had to comment. You consider 60deg a cold start? The other day it was upto 55deg. That was our one day heat wave.

 

[EArp]

BTT



Had to comment. You consider 60deg a cold start? The other day it was upto 55deg. That was our one day heat wave.

Dude, that kinda puts it in perspective... lol. When I say "cold" I mean the first start of the day.

 

[GCP]

Tried the 2 stroke oil and the rough idle has disappeared. Can I order the FCA from the Cummins website?



Thanks for your help.

GCP

 

[cerberusiam]

Tried the 2 stroke oil and the rough idle has disappeared. Can I order the FCA from the Cummins website?



Thanks for your help.

GCP

Yes, or here. If you rrough idle is gone I wouldn't worry about the FCA being bad unless you have other issues. Just keep running the extra lube.



Common Rail

 

[GCP]

I'm going to pick up a new FCA from the local Cummins dealer this weekend. Anyone have any tips or tricks for replacing the FCA? It looks easy enough.

Thanks,
GCP