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Discussion Starter · #1 ·
I just bought a 2006 Ram 2500, 70K miles. I am new to Diesels so maybe someone could offer some help. if i put it in neutral and hit the throttle to about 2,000 RPM's the motor will hang and rev for about 10 seconds before returning. Also when I am driving at about 1,400 RPM it seems to sputter a bit. any ideas would be helpful.
 

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my guess is you need injectors mine hung at 3500 rpm and wouldnt come down till the key was turned off pooched injectors was the prob.
Do you run a rail pressure box.

side not you should fill out your sig with mods and options it will help other members know what you have
 

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Discussion Starter · #3 ·
I am a diesel rookie, i have only had the truck 2 mos. the truck is pretty much stock. I bought it from a dealer, it was a trade in, it has an ARC intake and flow master exhaust. I will update my profile. thanks.
 

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Discussion Starter · #4 ·
i took it to the dealer today (my friend owns the dealership and it under warranty, so i tend to believe the tech. they said nothing came up on the codes and everything checked out? they said it could be some sort of aftermarket programming that they can't detect, or something to do with the aftermarket intake and exhaust. kind of at a loss, i don't think it is right?
I have plenty of power, but it hangs pretty hard at 2,000 rpm.. However they are replacing my steering gearbox and stabilizer for nothing?
 

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Most of the common rails i have driven hang like that. They are not very responsive and dont like dry revs cause it takes 5 seconds to come down. I was told by a tech that it is caused by the boost in rail pressure when you rev and the pcm wont slam the injector on time shut with a high pressure like that. Mine does the same and i hate it.
 

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your rpm hang is normal on a CR Cummins. takes several seconds for the rail pressure to drop from high rpms especially if in neutral. no load on engine thus ECU is telling the injectors to inject minimum diesel from the rail.

if you do have leaking injector needles, watch the oil level like a hawk. a tip leaker can dump lots of diesel into the oil in little time.
if you notice the oil level rising any at all, send an oil sample in to an oil analysis lab and have them test for diesel in the oil. notify your dealer if the test comes back positive. dealers don't have a decent test for leaking injector needles.
only solution is to pull the injectors and send in for testing.
 

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Discussion Starter · #7 ·
thanks for the help, i will keep digging. maybe i can find someone local that knows more about it, and can test it, other than a dealer. (pretty sad when the dealer tells you they have no idea?).
 

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My brother had the exact same problem as you. If you look at my post its pretty much the same thread. We took it into the dealer for a reflash and the problem stopped.
 

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good idea, get it reflashed. used unknown truck and programmer history.
 

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Discussion Starter · #10 ·
Do they make chips for these trucks? could the truck have a chip in it? would the dealer know by a diagnostic? Would the ARC intake and Flowmaster exhaust require a reprogramming? if they re flashed it would it mess anything up?
 

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dealers don't have a decent test for leaking injector needles.
only solution is to pull the injectors and send in for testing.
I had an 03 Dually auto 305/555. It had an injector shield leak, and the dealer put some flourescent dye in the crankcase, and it showed the leakage. I discovered the leak when I noticed a strong fuel odor under the hood, coming out of the vent tube. Plus my fuel mileage was really bad, so I pulled the dipstick and voila, it was about 2" above the full line. Thanks.
 

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I'm buying a 2005 cummins 5.9, I tried it out and it's running good however it has almost the same problem. You rev it up and it is very slow to go back to idle. It almost does it in steps.
Injectors?
I am an automotive mechanic, but never worked with diesels. Please help
 

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i have an 05 myself it does the very same thing its kinda depressing haha but it runs great in all the forward gears. i think personally its the boost pressure not allowing the rpms to drop in the rail be cause the pcm wont shut in time so its cutting your fuel down
 

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Mine does the same thing. It actually works well with my manual as the revs don't drop enough to cause me to give it much throttle when downshifting. Definitely different from my '98.5. I'll still take this one. pretty nice they gave you a new steering gearbox. You're off warranty with an '06 w/70,000K
 

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The more I research this the more I find people saying this is normal. The most convincing thing I read was allegedly the common rail system requires a little bit of time for the fuel pressure to drop, which makes the engine rev down slowly; something about avoiding damage to the injectors, which are electronically controlled. The dealer told me if they look at it and find no issues, it would cost $80. They won't find any codes. I guess I'll just make sure I don't punch it when I'm on someone's tail! I would not blame the injectors, as long as it runs smooth/no smoke/no fuel in the oil.
 

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no it seems to run good, i'm just nervous about buying it !!!, so you guys think is ok, i wont have to spend an extra 5k to fix ?
it's not just slow to come back but it does it in steps....
2000, 1800 1600 1400 1200 rpm and then back to idle... normal?
it just happens to be parked beside couple of other rams...
one 04 other 06 and neither of them does tha same thing .
 

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WEEEEELLLLLLLL..............Since you put it that way......maybe one of the other trucks would be better. I guess warranty is the key. I mean, it is likely something in the electronics....computer controlled and all. If you buy it and they stand behind it, all you are out is time.
 

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Discussion Starter · #18 ·
I called a local cummins shop and they said this is a proprietary engine for dodge and they do not work on these engines. They suggested i keep trying dealers until I find a good diesel mechanic. Taking it in tomorrow to dealer #2. I am getting about 15 mpg, I guess i was hoping to get between 18 and 20? does that seem right? what should I be getting for fuel mileage? So far my "Awesome bullet proof kick #ss Cummins run forever diesel" is not working out like i expected??
 

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Wow that kind of sucks, but not surprised; some of the dealer mechanics are young and inexperienced; maybe you can find a rural Dodge dealer with a guy that is really good, rather than some place in the city. I guess ask the service manager. 15 sounds a tad low, depending on driving conditions. I could see it with mostly in town driving. I hear some guys complain when they got a dually quad cab 4x4 with 4.10 gears and only get 13. Kind of silly. If you want 20 mpg, better buy a 3/4 ton 2wd regular cab. 2000 lbs makes a difference.

During my mid life crisis I've owned an 01 with 3.55/47RE and got 18.5-19 hwy @70, then an 03 6 spd/3.73 (both QC 4x4), 20 [email protected]; then an 03 dually QC auto 2wd 3.73 between 14-21 hwy @ 65 (from 30 mph headwind to light wind); current truck 06 QC 4x4 3.73 48RE I got 16 on the first tank beating the snot out of it (ran it 75 coming home 150 miles from the dealer last month, then floored it regularly driving around here-moo hoo haa haaa) Should be able to pull down 17 average, computer shows 17.5 now and in my varied experience it is pretty close in warm weather; cold it reads about 2-3 mpg more that actual. All my trucks were stock, the tires @ 80 psi. In retrospect I also had an 06 1500 hemi QC 20" 3.73 auto, and averaged 14-15 hwy, and got 8 mpg towing @65. For petes sake don't do what I did-buy what you want the first time and keep it. LOL!!!
 

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Discussion Starter · #20 ·
I've got to give credit to my stubborn retired dad. He lives in farm country and went to the local dealer. Make sense 99% of the farmers around here have cummins trucks. Long story short I talked to the diesel mechanic, it is not normal!!! I explained the symptoms and he said it is most likely a bad injector or two.(like a few people mentioned in this forum) He said the problem is the pressure in the fuel rail, usually with a leaky injector you lose rail pressure and the computer is confused because you are off the throttle, yet the rail is not under full pressure so the computer is not sure whats up. Also the pressure is dumping fuel thru the leaky injector making the truck run for a while until the fuel is burned off. its at the shop now, i will let you know how i make out.
 
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