OK about a year ago this came on. I filled truck at a place I have never been before. Couple hours later truck ran rough at idle, then went away. This has happened several times over the past year. I checked the wires at the A/C compressor and wire loomed & taped them up (cronic problem on 03). When this happens it seems like the truck is misssing or running on 3 cylinders. I never get a code. I don't think it's a sensor, cam or crank, cause it comes and goes???? This is what I suspect. I keep the truck in a heated garage, the fuel tank is drawing condensation and therefore I am having some type of water problem???? I service the truck myself and never have pulled any water from the seperator. I also treat the fuel with Amsoil Diesel conditioner..... So if the conditioner is absorbing the water is that the rough idle I am feeling. I also suspect some type of fuel issue cause a soon as I take it out and run the hell out of it it goes away???
Ant thoughts or suggestions..... maybe a sticking injector???? maybe run some other cleaner though it???

 

mine does that to sometimes. its a 2004.5 my wires werent rubbed tthru ut why would that affect idle?

 

The A/C compressor and the cam sensor share the same wiring and there has been problems with the wires chaffing and going to ground. This was causing a rough running condition with no codes. I'm almost sure mine is FUEL related.

 

My '05 does this too. I can't find any rhyme or reason to it. Sometimes it goes weeks or months without doing it, and then sometimes it does it off and on for days on end. I have looked into fuel supplier, filter change interval, addative or not, etc. I can't figure it out, but at about 99,000 miles I can't find any adverse affects either. My last oil sample said the motor is better than average at its milage.

 

mine started it last week too (03)first time, did it three days in a row now nothing I also suspected fuel so i filled the tank and added Power service as usual and no problems again I also checked my wires for rubbing and it looks like they have already been addressed.????????

 

my truck idles fine at 750 rpm ALWAYS. and when i manually set cruise to 1100 rpm at idle its flawess aswell. where i run into rough idle is when its cold outside and truck automatically idles up to 1000 rpm. then it sounds like ****(crap). people look at it when its idling outside in a parking lot. people often ask me if its cammed somehow because the way it sounds. ????

 

I had read once somewhere that they will run on 3 cylinders to help the warm up process. And that is what mine sounds like when it does it. But the question still remains if that is what it is supposed to do then why does it only do every now & then??

 

My truck had a poor idle. Almost a stumble at times. It would have a slight surging when it was cold. I replaced the FCA with the one from that Arson II kit and the problem went away. It could also be a bad lift pump, or so I'm told.

 

There's no 3 cylinder idle on a 3rd gen.

ya

 

THANKS, Wasn't sure about the 03's and 3 cyc. deal. My CP3 is only about 1.5 years old so I can't imagine the FCA not working corectly.. Plus it is only so random.

 

Mines done this this winter to. was sure it was a sensor issue. finally got it to the dealer and the checked it out and they said its injectors. one or 2 dont work right and let to much fuel in or something. weird thought it only shows up at the high auto idle. but after they told me to rev quick and see how much it hangs on. it was hanging up and they said thats an injector issue too. so they went through there waranty line or what ever and got the Ok to change all 6. i think theyre goning to run some more tests on thursday afternoon when i bring it down again. (maybe to please waranty dept.?) then go ahead and change them. im getting dinnged though for them to take out the fuel tank and flush it they said they always do that to get a clean start? why cant the fuel filter catch all the bad stuff that screws up injectors?

 

tell me if the injectors helped.

 

They're scamming you on the tank flush. That's what the fuel filter is fore.

 

can you do just the tips or whole injectors? whats best deal?

 

05 Ram,

what happened?

my 06 stumbles and bumbles at idle.

regular idle & high idle

I sit in it, parked a lot, waiting on my wife, so i feel it rocking.

all stock.
Fuel MPG has gone UP a lot, which is weird.