12 Valve 2nd Gen Dodge Cummins 94-98 Discussion of 12 Valve 5.9 Liter Dodge Cummins Diesels with P7100 Injection Pumps

Dead Cylinder

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Old Jan 5, 2011 | 06:34 PM
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Default Dead Cylinder

So the story begins while on a 500 mile trip at about 450 miles or so, got the cruise set at 75 while coasting down a hill... Start to return up the next hill and POP! It continues to pop thru the exhaust and obviously has a dead cylinder. Pull over looking for blow by, oil, ect. All i find is fuel leaking from between the exhaust manifold and head. Being as im going to school in Indy had to have it towed the other 50 miles and with no place to tear into it at i had to resort to calling the ole' dad! Im not happy about this, because automatically the jokes start (duramax guy). I have never had any problems with this truck, no blow by, never had anything wrong with it that isnt reasonable, like starters and things like that. He calls me today with results to some research and it seems to be an injector. Has anyone else just had an injector take a poop all of a sudden like this? We arent for certain but it all adds up because number one cylinder was completly dead. So he swapped number one with number two injector and now number two is the dead cylinder. We have an injector coming in the morning to say 100% what it is. Any insite would be helpful, thanks in advance!
 
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Old Jan 5, 2011 | 06:53 PM
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Like anything mechanical, they get tired and do fail. I wouldnt worry if the #1 fired with the other injector
 
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Old Jan 5, 2011 | 07:36 PM
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how many miles are on your injectors? over time if the pop press fades enough it can cause pintle problems
 
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Old Jan 5, 2011 | 07:39 PM
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I was bragging on the truck that night because it just rolled over 294k. I have been trying to narrow down a rough idle issue in the summer time and have wondered if the injectors having that many miles on them and pop pressure possibly being low if that would cause it.
 
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Old Jan 5, 2011 | 08:08 PM
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Originally Posted by BRE
I was bragging on the truck that night because it just rolled over 294k. I have been trying to narrow down a rough idle issue in the summer time and have wondered if the injectors having that many miles on them and pop pressure possibly being low if that would cause it.
Tell the dad to talk when he has 294k on the Dmax
 
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Old Jan 5, 2011 | 08:29 PM
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Originally Posted by BRE
I was bragging on the truck that night because it just rolled over 294k. I have been trying to narrow down a rough idle issue in the summer time and have wondered if the injectors having that many miles on them and pop pressure possibly being low if that would cause it.
yeah, low pop pressure can cause a hazy low idle. At least thats what mine did when a few were 30 bar off
 
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Old Jan 5, 2011 | 08:33 PM
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sounds like an easy fix
 
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Old Jan 6, 2011 | 11:50 AM
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We will see when i hear from him today if that was the total problem. What do you guys think i should do? The way i see it if one is bad with that many miles the rest are bad and on their way to failure as well possibly. Order a new set when money allows?
As for the dad, we both do quite a bit of mouthing back and forth but i do have a weak spot for the old duramax's. I just cant tell him that!
 
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Old Jan 6, 2011 | 03:30 PM
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just get your old ones repoped and cleaned ... unless you want another set than that is a great excuse
 
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Old Jan 6, 2011 | 04:57 PM
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I want some new ones of course!!! I just dont know what size to get! Im going sdx.... just dont know what size i want.
 
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