LBZ Turbo break only works sometimes??

LBZ_Baker98

Member
Jul 8, 2016
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Texas
Ive got a 07 LBZ withe EFI Live. My turbo break only seems to work sometimes? If i'm going like 65 or 70 and roll into the throttle hard sometimes the turbo break will start working when i let out of it. I thought maybe it just had to sense a load on the truck before the turbo brake would work but i have been towing a trailer for the last 3 days that weighs roughly 7k lbs and the turbo break has only worked once? Any ideas or help is greatly appreciated!
 

clrussell

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Sep 23, 2013
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Generally the turbo brake tuning is 2000 rpm and above.. try down shifting to get the rpm up and see if you notice it then.
 

LBZ_Baker98

Member
Jul 8, 2016
208
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Texas
Generally the turbo brake tuning is 2000 rpm and above.. try down shifting to get the rpm up and see if you notice it then.

sorry, forgot to mention i tried that. When the turbo brake decides to work i can watch my boost increase while slowing down and i can hear the turbo. I have down shifted to where the RPMS were up at 3000 and it still doesn't work. The few times it has worked its been fantastic and slows the truck and trailer down really well!
 

clrussell

pro-procrastinator
Sep 23, 2013
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Did this just start or always been this way? There's a few factors in the turbo brake side of the tune.
 

LBZ_Baker98

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Jul 8, 2016
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Did this just start or always been this way? There's a few factors in the turbo brake side of the tune.

It's always been this way. Ever since I got it tuned it's been hit or miss! Could it be something in the tune causing it? If so what I'm the time could cause that? Thanks!
 

LBZ_Baker98

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Jul 8, 2016
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Texas
Also on a cold morning when I first start the truck it usually works good for a couple miles then stops when it warms up
 

JoshH

Daggum farm truck
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Feb 14, 2007
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If your turbo is working fine other than that, it's a tuning issue.
 

IOWA LLY

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Feb 23, 2007
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Your vanes could be sticking....


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THEFERMANATOR

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Feb 16, 2009
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Guess I've been lucky, but all the lbz's I've done just flat WORKED! So much better braking than the lly's I've done. But the switch to activate the factory one is supposed to work far better.
 

LBZ_Baker98

Member
Jul 8, 2016
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Your vanes could be sticking....


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Is there a way to check that? I need a scanner that will monitor vane position correct? I can hear my turbo vanes open and close at idle when I start it up after its been cold so that makes me think they aren't sticking but I've been wrong plenty of times!
 

LBZ_Baker98

Member
Jul 8, 2016
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Okay just started the truck up this morning and took off. Turbo brake worked great when the truck was cold. I was going down a hill and the turbo brake was working great then stopped working after about 3 or 4 miles once the truck got warm?
 

clrussell

pro-procrastinator
Sep 23, 2013
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Sounds like tuning still. Pretty sure there's a table for max vane pos that's coolant temp
Based?
 

IOWA LLY

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Feb 23, 2007
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Is there a way to check that? I need a scanner that will monitor vane position correct? I can hear my turbo vanes open and close at idle when I start it up after its been cold so that makes me think they aren't sticking but I've been wrong plenty of times!



That's a good indicator, but sometimes they don't stick when cold, but do when hot.

A good scan tool will work. You need to check for proper operation when up to temperature.


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hondarider552

Getting faster
May 28, 2008
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Max vane tables, commanded boost at 0% throttle all have a role. I've had a brake work all the way down to 1200rpm in my last LBZ.