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Discussion Starter #1
After a good 1200 or so miles on the clock, I find little hiccups in the tuning of this engine. One the most notable is while in park. When you slowly raise the rpm depressing the peddle, the engine starts to hunt very irratically at between 1200 and 1800 rpm then smooths out around 2000rpm. Pretty huge flaw as I've never had a diesel do that before. It's not a function of limiter because it returns to rock solid at around 2k on the tach. The tach needle is bouncing almost 300rpm or better.

The other oddity is with random starts that you can hear a slight hunt or even a morning or two that produced what sounded like misfires and more diesel smell than usual (almost like fuel was fired after the compression stroke). Now this could be a flawed attempt at the ECU trying to get exhaust temps up as soon as possible, but it really needs more refinement. Going to have the dealer contact Cummins for a visit. Figure I can give them a better snapshot of the issues in person. No codes are set but definitely annoying. Chime in if you all are experiencing the same issues so I can give them a number of affected vehicles.

BigRed
 

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I'm wondering if it has to do with the gate and how it controls flow from the 2 different turbos. Seems almost like it is wanting to switch back and forth under an unloaded condition.
 

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Discussion Starter #3
It's possible, but since its light load, you'd think primary flow would stay on the small first stage turbo. Hopefully the reps will shed some light on it. Shocked it's only mine...lol.

BigRed
 

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It's possible, but since its light load, you'd think primary flow would stay on the small first stage turbo. Hopefully the reps will shed some light on it. Shocked it's only mine...lol.

BigRed
Chances are if you're the only one noticing this, you have a problem & it's not just a "Programming issue". I'd definitely take it to the dealer so they can have a look at it.
 

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After a good 1200 or so miles on the clock, I find little hiccups in the tuning of this engine. One the most notable is while in park. When you slowly raise the rpm depressing the peddle, the engine starts to hunt very irratically at between 1200 and 1800 rpm then smooths out around 2000rpm. Pretty huge flaw as I've never had a diesel do that before. It's not a function of limiter because it returns to rock solid at around 2k on the tach. The tach needle is bouncing almost 300rpm or better.

The other oddity is with random starts that you can hear a slight hunt or even a morning or two that produced what sounded like misfires and more diesel smell than usual (almost like fuel was fired after the compression stroke). Now this could be a flawed attempt at the ECU trying to get exhaust temps up as soon as possible, but it really needs more refinement. Going to have the dealer contact Cummins for a visit. Figure I can give them a better snapshot of the issues in person. No codes are set but definitely annoying. Chime in if you all are experiencing the same issues so I can give them a number of affected vehicles.

BigRed
My truck does the samething. Did you ever get your truck looked to figure out the problem?
 

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Discussion Starter #6
My truck does the samething. Did you ever get your truck looked to figure out the problem?
Currently trekking across the country, but on a side note, the truck as soon as it passed 6000miles is a whole different animal, which definitly makes me wonder about a break in component in the software. The truck was flashed a while back, haven't tried the hunt check from cold start, doesn't do it warm. There is still a very slight hunt in idle cold, but maybe 25rpm, pretty small but no fuel smell. I think from the data they have rolling in, things will get better. But have been driving the crap outta it and will report on my trip home with trailer...1600miles.
 

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As mentioned in another thread. These trucks need to be worked. They are grossly overbuilt for there rated duty. Get over 6000 miles.
Then look at economy, regens, power delivery, tranny shifts etc.... You will find a totally different truck in all those aspects. It needs to be worked, it needs to be driven. But if used only used as grocery getter that whole break-in process will take that much longer.
 

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I currently have 4200 miles on it now other then the alignment issue and the flash update l love this truck. I do have to take back to the dealer for them to attempt the alignment again.
 

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After a good 1200 or so miles on the clock, I find little hiccups in the tuning of this engine. One the most notable is while in park. When you slowly raise the rpm depressing the peddle, the engine starts to hunt very irratically at between 1200 and 1800 rpm then smooths out around 2000rpm. Pretty huge flaw as I've never had a diesel do that before. It's not a function of limiter because it returns to rock solid at around 2k on the tach. The tach needle is bouncing almost 300rpm or better.

The other oddity is with random starts that you can hear a slight hunt or even a morning or two that produced what sounded like misfires and more diesel smell than usual (almost like fuel was fired after the compression stroke). Now this could be a flawed attempt at the ECU trying to get exhaust temps up as soon as possible, but it really needs more refinement. Going to have the dealer contact Cummins for a visit. Figure I can give them a better snapshot of the issues in person. No codes are set but definitely annoying. Chime in if you all are experiencing the same issues so I can give them a number of affected vehicles.

BigRed
Did you ever get anywhere with this? I have the same issue and can feel a slight blip while driving, Thanks for any info.
 
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