Bad demandate
12-19-2023, (Subject: Bad demandate ) 
Post: #1
Bad demandate
Hello all, I’m new here. I’ve got a cm870 that’s been demandated, and it’s running awfully. Making chuffing sounds at idle, similar to what I’ve heard when the fueling actuators go bad, but I’ve replaced all my actuators, rebuilt injectors when the engine got rebuilt 150k kms ago, plus a almost new gear fuel pump off of a wrecked truck. If I increase and decrease rpms the chuffing stops for a little while, then gradually comes back, it also vibrates in the cab when its chuffing. I did harmonic dampener, and watch Rawze’s video on how to time the compressor and did that too. I haven’t pressure checked the cac properly since last spring (found the cooler to be leaking excessively and replaced) but that didn’t make a difference on the chuffing. My pyro and boost seem to be erratic, sometimes I get 39 psi and the pyro wants to go to ten, next it’s only making 35 and the pyro is 8.5-9 (or vice versa, no real pattern there). Brand new holset turbo and actuator (it’s got a spacer in the actuator to make it run cooler. Check engine light is out, but it’s showing lots of egr codes (temp, valve position, differential pressure, valve control). I’ve replaced air inlet pressure and temperature sensor egr pressure sensor, crank and cam position sensors. Also, running down the highway sometimes it will pull very smooth, then randomly start vibrating, which I’ve determined must be the engine, because if I pop it in neutral and let the engine idle down, it’ll decrease, idle up, increase. I’m leaning towards bad demandate? I’d just go ahead and mandate it again to get rid of the problems, but that’s supposed to be 15k in parts, on top of a bad egr design from what I’ve heard that has its own fair share of problems. I bought it demandated. I’m hoping someone here can help,thanks!
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12-19-2023, (Subject: Bad demandate ) 
Post: #2
RE: Bad demandate
Have you checked out your exhaust pressure sensor / intake pressure sensor? Either one reading incorrectly can cause all sorts of weird issues. It very well could be a bad demandate as well.
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 Thanks given by: Oilysnowman
12-19-2023, (Subject: Bad demandate ) 
Post: #3
RE: Bad demandate
It is a CM7870 ... Take it to any stealers#it and have the ecm flashed with the proper factory programming according to the engine ser#. It will not shut down on you, but only have check engine light on.

It can be driven in its factory built-in NON-EGR operating mode by simply unplug the EGR temperature sensor, and then driving it like that until you can get all the mechanical gremlins out of it.

Boost will spike about 36 or so then fall back to 32 when in this condition... and NO it should not be 'chuffing' and all sorts of other garbage.

http://rawze.com/forums/showthread.php?t...0#pid71360

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once it is all straightened out and all the mechanical problems fixed.. then get with forum member 'running rough' to have a proper de-mandate program made for it again.


User's Signature: ->: What I post is just my own thoughts and Opinions! --- I AM Full Of S__T!.
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 Thanks given by: Oilysnowman
02-19-2024, (Subject: Bad demandate ) 
Post: #4
RE: Bad demandate
So update as to where I’m at. Went to the dealership, told me couldn’t touch my truck with it being demandated. So I got running rough to do his magic. Works way better now! Idles smoother, pulls smoother and sounds way better! Still got a little hiccup when I listen to the exhaust, but the engine noise is very smooth listening from beside the engine. so I did the injector bubble test (no bubbles) did an over head adjustment (sounds a tiny bit smoother and in cab vibration went away) but I found some pitting starting on one rocker roller and polishing is different on every lobe on the cam shaft. Insite cylinder cut out test runs on every cylinder but number 2 and 5 lose a good hundred rpm’s more than all the rest. Hoping for some advice regarding that, and I also plan on running this cam shaft until spring when I get a month or two off anyway then replace. Is this a bad idea?


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02-19-2024, (Subject: Bad demandate ) 
Post: #5
RE: Bad demandate
Also, found my turbo actuator control box to have an air leak, so I’ve ordered a new one. Supposed to be in this week yet.
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02-20-2024, (Subject: Bad demandate ) 
Post: #6
RE: Bad demandate
(02-19-2024 )Oilysnowman Wrote:  So update as to where I’m at. Went to the dealership, told me couldn’t touch my truck with it being demandated.

Did you tell them you brought it in to be UN DEMANDATED ?? It doesn't make sense that they wouldn't flash a factory file into it.

Glad to hear you got it going in the right direction though.
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02-20-2024, (Subject: Bad demandate ) 
Post: #7
RE: Bad demandate
(02-20-2024 )tree98 Wrote:  
(02-19-2024 )Oilysnowman Wrote:  So update as to where I’m at. Went to the dealership, told me couldn’t touch my truck with it being demandated.

Did you tell them you brought it in to be UN DEMANDATED ?? It doesn't make sense that they wouldn't flash a factory file into it.

Glad to hear you got it going in the right direction though.

I did tell them that, they told me I’d have to find the guy who demandated it and get him to reflash it… they didn’t seem all that knowledgeable to be honest
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02-20-2024, (Subject: Bad demandate ) 
Post: #8
RE: Bad demandate
(02-19-2024 )Oilysnowman Wrote:  Also, found my turbo actuator control box to have an air leak, so I’ve ordered a new one. Supposed to be in this week yet.

That turbo box can cause a lot of pyro issues too. Going through the same thing.
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02-21-2024, (Subject: Bad demandate ) 
Post: #9
RE: Bad demandate
(02-20-2024 )Benjamin9669 Wrote:  
(02-19-2024 )Oilysnowman Wrote:  Also, found my turbo actuator control box to have an air leak, so I’ve ordered a new one. Supposed to be in this week yet.

That turbo box can cause a lot of pyro issues too. Going through the same thing.

Did you change yours already? If so, what differences did you notice?
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