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

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wjburken

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Possible. I've never looked into it.

I looked into a couple patents for VFFS systems and it’s kind of interesting how they can take a combination of known Stoichiometric ratios of E85, E10 and E0 fuels, fuel line pressure, injector settings and rich/lean measurements of the O2 sensors and is able to calculate the % of alcohol. It goes into a relearn mode when ever the system detects an increase in the fuel level in the tank.
 

HiHoeSilver

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I looked into a couple patents for VFFS systems and it’s kind of interesting how they can take a combination of known Stoichiometric ratios of E85, E10 and E0 fuels, fuel line pressure, injector settings and rich/lean measurements of the O2 sensors and is able to calculate the % of alcohol. It goes into a relearn mode when ever the system detects an increase in the fuel level in the tank.

Yeah, I read that it closes the purge solenoid and takes closed loop data to figure it out. It only goes into learn mode when it sees 3 or more gallons, which triggers a refueling event. I ran out if gas once and only had access to 2 gallons of 87 octane and it got all goofed up. I had to reset it with the scanner.
 

iamdub

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Speaking of refueling events, I heard that the PCM adjusts for a calculated loss of octane rating. It factors the elapsed time since the last refueling event and the calculated octane rating (probably by knock detection/retard tables) of the last drive cycle to estimate the remaining octane rating of the fuel and factors that into it's ignition tables. When you refuel, it starts over.

A tuner told me this after I mentioned how much better my Tahoe feels so quickly after a fresh tank of 91-93 is poured in. Since mine sits for so long and is refueled once, maybe twice a month, I'm probably only getting the full 91+ octane benefit for the first week or two.
 
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Removed the "DeSlugger" from the AC plug. Didn't like the way the AC acted when first started, it also made weird clicking noises.

While under there, I noticed the drivers side sway bar endlink end is broke at the control arm. Typical rust through the bolt.

I had to replace the ones on my 2011 when I first bought it. It wouldn't pass inspection for me to get my plates. I also had to replace the ball joints also.

It really sucked, replaced that stuff on the front end so I could get plates, then it was totalled by a drunk driver running a red light 2 months later. [emoji51]

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18
 

Rocket Man

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Removed the "DeSlugger" from the AC plug. Didn't like the way the AC acted when first started, it also made weird clicking noises.

While under there, I noticed the drivers side sway bar endlink end is broke at the control arm. Typical rust through the bolt.

I had to replace the ones on my 2011 when I first bought it. It wouldn't pass inspection for me to get my plates. I also had to replace the ball joints also.

It really sucked, replaced that stuff on the front end so I could get plates, then it was totalled by a drunk driver running a red light 2 months later. [emoji51]

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18
What’s a deslugger? Or an AC plug for that matter? Am I missing something?
 

petethepug

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Removed the "DeSlugger" from the AC plug. Didn't like the way the AC acted when first started, it also made weird clicking noises.

Thanks for posting the deslugger follow up report. Ironically the wifey heard our a/c knock on start up last week. I’m getting into the habit of starting the truck w/ a/c off.



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Doubeleive

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20 min drive. Nothing major to report


View attachment 230942
I swapped my original cluster back in that I took out 25k miles ago, it shows 10.7mpg same as I am getting now with the new cats so I'm probably right where it's going be I guess, getting the ppv cluster worked on tomorrow i'm going to have like $500 invested in the dam cluster :bawl:
 
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What’s a deslugger? Or an AC plug for that matter? Am I missing something?
Plug=wire harness plug that plugs into AC compressor.

DeSlugger is a little electronic box that plugs in-line to the above discribed plug.

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18
 

Rocket Man

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Plug=wire harness plug that plugs into AC compressor.

DeSlugger is a little electronic box that plugs in-line to the above discribed plug.

2001 Yukon SLT
2012 Yukon Denali XL
2011 Yukon Denali RIP 5/20/18
I never heard of the compressor slugging, not sure where I’ve been all these years lol. Mine don’t do it, is it just certain compressors or models?
 
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