New Turbo and still NO boost. HELP!!!

freestylest22

New member
May 17, 2015
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0
0
Springtown Texas
I just bought a 2006 LBZ with 90k miles on it. It had a low power/no boost issue. I put a Dannville Stage 2 GT3794 turbo on it. Along with egr delete, heater grid delete, fuel rail shim, 3" downpipe to 4" exhaust. I'm running EfiLive by Idaho Rob. Truck still only produces 24psi at max and that's at WOT in the higher RPM's. It's a very lazy turbo spool. The exhaust bellow on the egr port blew so then I thru more money at it with ProFab exhaust manifolds and up pipes. Truck is still weak/slow. Where should I look next? ANY help is greatly appreciated.
 

freestylest22

New member
May 17, 2015
32
0
0
Springtown Texas
He's adjusted for the turbo 3 times and still no low rpm boost. And this turbo should do 35-40 easy. No, I haven't pressure tested the system. Dropping it at off Friday at Texas Diesel Power in Weatherford to have them look at it again. They did all the work to it.
 

clrussell

pro-procrastinator
Sep 23, 2013
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What are you using for a gauge to read boost?


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pizza pig

I Like to Party
Feb 13, 2012
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CT
pizza pig, are you talking boost or fuel pressure test?

Pressure testing as in, boost testing charge system to check for boost leaks. If this shop did all the work and let the truck so running like crap with no boost, you sure you want to take it back there?
 

freestylest22

New member
May 17, 2015
32
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Springtown Texas
I'm giving them one more chance. I didn't have it tuned when they did the turbo and deletes, so they couldn't really "test drive" it. I did the up pipes and manifolds. I'm using my CTS 2 to read the boost.
 

clrussell

pro-procrastinator
Sep 23, 2013
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The cts probably won't read much over 24 since it uses the stock sensor and I can't remember what an lbz sensor maxes at...

I'd check the y bridge depending on the egr kit, that and the connection at passenger side intercooler. Both prime suspects with after market parts.


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freestylest22

New member
May 17, 2015
32
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Springtown Texas
I'm in Springtown, just North of Fort Worth Texas.
I'm using the trucks stock boost sensor. I'm ordering the EAS as I bought the expandable egt probe.
The truck has a dark haze smoke as it's climbing in rpm and SLOW boost at WOT. A turd for even a stock truck.
What do I need to check on the Y-bridge?
I also had this problem before the new turbo and had the chevy house where I bought it and diesel shop say it was a bad turbo. But it was interment then. Now it's all the time with an occasional WOW and the truck will run.
I'm having Idaho Rob build another tune for it again since I've added the up pipes and manifolds.

Also thinking about adding the S&B cold air kit. Dry. Any thoughts on this? I've done the air box mod.
 

duramaxzak

Wanna be puller!
Nov 22, 2008
2,431
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Minnesota
The LBZ Y-bridge is two pieces, they can blow apart and leak. There is a big o-ring holding them together. Also have the factory intercooler and pipes pressure tested. Was the turbo vein position sensor replace when the turbo was replaced or was the old one used?
 

freestylest22

New member
May 17, 2015
32
0
0
Springtown Texas
Duramaxzak, that's a good question, I'm not sure on the sensor. I'm going to pressure test the system myself today. Is there a good aftermarket Y bridge for the LBZ? If mine is busted and is it a pain to replace? I'm SOOO ready to get this truck running right.
 

JoshH

Daggum farm truck
Staff member
Vendor/Sponsor
Feb 14, 2007
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Texas!!!
I think pretty much everything has been covered already, but if you need someone else to take a look at it, I'm about 70 miles east of Dallas on I-20. I'd be happy to figure it out for you.