Hello all,
I've been having problems since December or January with my truck revving up while idling. First I changed my injectors (was told it could be the culprit) and was suppose to have FCA looked at and changed if needed (mechanic "forgot" to check FCA).

Still revved up

Next I had a FCA code so I bought a bag-o-parts that came with FCA and changed all that out on injector pump.

Still revved up

So I went to another mechanic to have rail pressure sensor and throttle position sensor checked. Both checked out fine. But he did tell me it could be my Quadzilla Adrinaline causing it. So I ordered a Smarty and pulled the Quadzilla. Went through a hassle of trying to get the smarty to load because Quadzilla had messed up ECM. Took it to the dealership to get reflashed but the couldn't communicate with the ECM and told me I'd have to get a new one.

The whole time the truck would rev up periodically while idling. Sometimes multiple time in a day.

I ordered a new ECM installed it and installed my Smarty no problems. It's been about 2 weeks and then all of the sudden today it revs up 2 times within about a 8 minute period. Pulled out the Smarty, and no codes everything is clear.

***???

I'm stumped what do I check now? Why does it keep doing this?

When it revs up it goes to 2,300-2,500 rpm then right back down.

Any help or advice is greatly appreciated.

Thanks

 

Mine use to do the exact same thing......but....the new FCA cured my problems. Not sure where to tell you to look next. Maybe check for a good, solid connection at the FCA plug.

 

I'll check all that again. I feel like I've checked all that 3-4 times already. Maybe I have a short some where, or maybe this FCA is faulty too, but it's not throwing a code.

Thanks for the advice

 

I have an issue where the fuel pressure goes up when you put it in gear standing on the brake but the RPMs do not move till you take your foot off the brake and it almost jumps. Mine only does up to 1700 rpm and does it everytime I put it in gear. I have changed all the "culprits" and have an appt on friday to have the computer reflashed. Good luck and I will be following this thread to see what you find out. JP

 

Look at your torque convertor.

If the truck idles back down when the tranny is put in park (and possibly neutral) that indicates the TC is sticking when it is in Drive and you are stopped at a stoplight.

 

Isn't there an idle up feature built into the ECM programming. I think it is to keep the oil pressure up when a truck is left idling. Idling is something Cummins or Dodge does not want you to do?

 

Kurran sorry to hijack your thread. How does one check the TC? JP

 

Well I have a 6 speed so it only does it while sitting in Nutueral idling. It revs up like somebody is sitting in my truck and wants to show everybody outside of it how loud it is.

It's not a slow idle up like when its cold out side and truck idles up to warm up. This is just a quick rev up from 850-2500 and back to 850.

I've checked to make sure all harnesses are tightly plugged in this morning and they are. Luckily truck hasn't revved up since I posted this thread, but I'm betting it will do it again.

Could this be a sign of injecter pump going out?
I really thought the ECM being F*%€# up was the cause. Apparently not unless there is some other computer that could be damaged?

 

That's exactly what mine use to do! Extremely annoying....I know what you're going through. The new FCA stopped all of that. Is there someone with a known good FCA who will let you swap with them just to rule it out? You said you replaced it but mine did it almost from the time it was new.

 

I have the Bag-O-Parts (or something like that) fro industrial injection, so I'd have to get a new FCA from them because its supposedly a higher flow FCA. I'll have to call them again, because the first time this happened after installing it I called and they said no this is a new part, it can't be it.

 

Well, I took mine to the local dodge dealer to have a reflash and low and behold they said I needed a new TC, to the tune of $1400. I left there and went to a local transmission shop and have it schedulded to have a transmission rebuild and tc replaced. It does have 175K on the original 48RE.

 

I'll be darned. It's crazy what all the computer controls on these trucks can cause nowadays!!!! At least you got it figured out and that's half the battle......the other half is coming up with the money to fix it....at least in my case anyways!!

 

Glad to hear you got your problem solved

As for mine, I hadn't had any problems since I started this thread,until yesterday. Truck decided to go ahead and rev up twice. I finally got a chance to call and talk to industrial injection, and they are sending me a new FCA. Hopefully this will solve my problem.

 

I am in Southeast Texas close to Louisiana Border. Where are you located at? Find a Cummins dealer usually a big truck shop. If this next FCA valve is bad. I will get you one from the Cummins dealer here for you. If you want me to. I think I paid $116 for mine

 

Sorry I know this reply is a week or so late. I'm a little south of San Antonio. I got my FCA from Industrial Injection Friday and put it in on Tuesday. I havent had the truck idling very much since put in so I'll have to see if this solved my problem.