Idle fluctuating

[Gilbert Lucero]

At idle my truck fluctuates(hot and cold), as soon as u give it fuel it runs like normal. It's throwing a P0191, it comes and goes in monthly intervals. I've changed: fuel rail and sensor, fca, fuel filter (twice). Are there idle sensors on the 2011 6.7? What are the symptoms of a bad cp3?

 

[Ozymandias]

How much fluctuating?

 

[Gilbert Lucero]

Very little, 50rpms or so. It's a pulsating sound, you can feel it in the wheels if the breaks are off.

 

[Jim W]

What are the RPM ranges when your cold and hot what is the variances between them at the different temps or are they the same? How long have this been going on since new or did this happen over some time?

 

[Gilbert Lucero]

550 to 600/650 when it pulses. I know diesels wob, but this isn't healthy and I'm throwing a P0191

 

[NIsaacs]

I know diesels wob,

wob ??

 

[Gilbert Lucero]

Wob wob wob* sound effects

 

[Ozymandias]

Well with your code I see the problem.

https://www.google.com/search?q=p0191+ram&ie=utf-8&oe=utf-8&client=firefox-b-m

 

[Gilbert Lucero]

What are the RPM ranges when your cold and hot what is the variances between them at the different temps or are they the same? How long have this been going on since new or did this happen over some time?

650-750 (hot and cold). I've owned the truck for just over a year, it's almost at 200k

 

[Gilbert Lucero]

Well with your code I see the problem.

https://www.google.com/search?q=p0191+ram&ie=utf-8&oe=utf-8&client=firefox-b-m

I'm thinking an injector is bad

 

[Gilbert Lucero]

wob ??

That was my attempt at sounding like a diesel, wob won wob

 

[Gilbert Lucero]

How much fluctuating?

650-750.

 

[Ozymandias]

One injector doesn’t make such a fluctuating idle - i think.
Maybe a little rough sound but not fluctuating.

Let's see what others think about it.

 

[Gilbert Lucero]

One injector doesn’t make such a fluctuating idle - i think.
Maybe a little rough sound but not fluctuating.

Let's see what others think about it.

That's just a ball park

 

[Jim W]

I would try sending a PM to either BOB4X4 or SAG2 both are former diesel techs for FCA/Dealer and they maybe able to help you with this issue.
Just a suggestion for you to follow up on!

 

[Gilbert Lucero]

I would try sending a PM to either BOB4X4 or SAG2 both are former diesel techs for FCA/Dealer and they maybe able to help you with this issue.
Just a suggestion for you to follow up on!

How can I get a hold of either one of them?

 

[Jim W]

OK; you need to start a conversation with them. To do that you need to enter your profile page under your name at the top RH corner. You than selected conversations on the drop down menu. Click on conversations and than on the top RH corner click start a new conversation and follow the directions.
Hope this helps?

 

[BIGNASTY]

Fuel filter plugged or Lift pump Maybe

 

[RamVenture]

Has anyone been able to resolve MIL code P0191 (Fuel Rail Pressure Sensor Circuit Performance). I've replaced the fuel rail pressure sensor, fuel control actuator (FCA) on CP3 pump and fuel filter twice in the last year. I've cleared the code as I haven't really noticed performance issue. Lately I have notice more idle fluctuation and code keeps coming back quickly. My truck is 2012 Ram 2500 completely stock with 145,000 miles. Attached is fuel pressure data logged. It looks to me my CP3 pump is able to make commanded pressure. I have a lot more data but CP3 can make from 5K to about 25K psi pressure. I would be interested in seeing others fuel pressure data. I would really like to get this issue fixed. Don't want to keep changing expensive parts. I've read if I had a bad injector I would see white smoke, but with DPF lifter we won't see white smoke on stock trucks. I get about 11.5/12MPG when pulling my 32ft trailer and about 14MPG unloaded. I'm thinking this about normal. If it's a bad injector it doesn't seem to be too bad. How long can you drive on a bad injector without causing other problems? Thanks for any suggestions.