What did you do to your NNBS GMT900 Tahoe/Yukon Today?

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j91z28d1

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saw a max of 13.4 deg knock retard in your first photo.
video shows you staying in knock retard.. I know what it feels like!

should be 0 knock for the most part..


is that what that means? I watched the video and didn't see that much.


in my hybrid tune 10deg is max. do you know what the max the normal trucks let your retard?
 

Doubeleive

Wes
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unless it's been changed max knock retard is 10deg and I didn't see it hit that so while it would be nice to have zero, seems like something the ecm can get on top of, or it would be maxed out retard..

I still am not clear even own truck if the timing shown is the actual timing with the knock retard removed or if that's like the base timing and you gotta remove the say 5-7deg in your head.


either way I don't believe that's why it's running bad but hopefully black bear will know if they need to reduce tuning a bit or let the ecm do its thing
the thing is there is no reason for this to be tune related at all, I switched it 3 times including going back to what was on it before blackbear sent me any tune and no change.
something is causing this just need to figure it out.
 

Doubeleive

Wes
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is that what that means? I watched the video and didn't see that much.


in my hybrid tune 10deg is max. do you know what the max the normal trucks let your retard?
I only recorded a couple minutes of the 9 minute run just to show what it is doing
 

mikez71

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max final timing maybe -10, but you can still have more retard.
So if his timing should have been 10 degrees at that moment, it would then be -3.4.
It's a lot of degrees, this is exactly what I felt with loose motor mount bolts.
 

Doubeleive

Wes
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saw a max of 13.4 deg knock retard in your first photo.
video shows you staying in knock retard.. I know what it feels like!

should be 0 knock for the most part..

check motor mounts, starter, anything close to the knock sensors that could be rattling..
i'll jack it up later and see if I can find anything, motor mounts were both replaced with the hummer mounts which should be ok but I will take a look
 

mikez71

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Original starter?

Regarding motor mount bolts,
I heard no noises, and only noticed one bolt was missing.
Put wrench on the other 3, all loose!
I must have forgotten.. was extremely tired/weak.. or. I'm not saying it was aliens.. but.
 

89Suburban

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Man what a PITA Wes! Sorry man! Wish i could be helpful.
 

j91z28d1

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max final timing maybe -10, but you can still have more retard.
So if his timing should have been 10 degrees at that moment, it would then be -3.4.
It's a lot of degrees, this is exactly what I felt with loose motor mount bolts.


I wonder where it's getting it extra timing amount to pull over max comes from.



I have wondered if the timing value shown is the actual at plug timing, or like you say, you gotta do the math and subtract the retard.
 

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