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  #1  
Old 06-01-2017, 12:06 PM
718Pinz 718Pinz is offline
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Posts: 27
Default Boost, EGT and smoke issues....

Hello everyone. I need some of your collective knowledge to help with my problems. Here is where I am sitting engine-wise:

Rebuilt motor bored to largest oversized pistons
12mm pump
Turbonetics Super 60 T3 with .82 ar
Turbonetics WG
Turbonetics manual boost controller
Air/water intercooler
Boost gauge
EGT
ARP Head Studs
3" DP

Now to the problems:

-Not building more than 10 lbs of boost...why?

-Black clouds of smoke (I think I about have this figured out)

-IP timing set to .96. Make minor adjustments with the inboard/outboard rotation. Outboard (to driver side) brings the EGT's down and runs better. Inboard raises EGT's and runs worse.

-Boost builds, then falls off at the high side of the rpm's. I initially thought it was due to excessive back pressure so I went up to a 3" down pipe. It helped with the smoke issue and seemed to help overall, but something is causing the boost to fall off and not reach over 10 lbs. My target boost is 20 lbs...just can't get there for some reason.

Any suggestions?

Thanks,
Phil

Last edited by 718Pinz; 06-01-2017 at 12:48 PM. Reason: Update about Boost falling off
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  #2  
Old 06-02-2017, 07:27 AM
v8volvo v8volvo is offline
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Location: Montana, USA
Vehicle: '86 745, '83 764
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Suddenly started doing this or been this way since it was first put together?

Sounds like an air inlet restriction issue. The smoke and high EGT suggests there should be more than enough drive pressure to spin the turbo but loss of boost with RPM says something isn't able to move enough air to keep up.

Where are you measuring boost PSI, after the intercooler or before it? If you are measuring it after the intercooler, have you checked pressure drop across the cooler?

What kind of air filter are you running? Checked vacuum on the turbo inlet?
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86 745 D24T/ZF 345k lifted 2.5"
83 764 D24T/M46 155k
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  #3  
Old 06-02-2017, 08:33 AM
718Pinz 718Pinz is offline
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I am pulling the vacuum off the back of the intake. We smoked the entire intake yesterday and found a small leak on a weld in one of the intake pipes just before the intake manifold. The silicone is good quality and pretty small runs in between hard pipes. I am running 3" into the turbo and 2.5" from the outlet to the intake, which is a very short run.

These problems have been there since it went back together. There is nothing obvious jumping out at me about this. I even took the air filter out of the box, just in case that was a restriction.
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  #4  
Old 06-02-2017, 09:30 AM
v8volvo v8volvo is offline
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Location: Montana, USA
Vehicle: '86 745, '83 764
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Good to fix the leak but it shouldn't cause boost to fall with higher RPM. Something about the way this setup breathes isn't right.

Are you able to check the boost pressure ahead of the IC? Eg from the wastegate signal line? You are sure the wastegate is seeing the same pressure signals the intake is? If there is restriction in the IC then that's going to cause the exact issue you are experiencing. Boost controller and wastegate the right parts installed the right way, correct spring choice, etc?

The 3" inlet, is that direct from atmosphere or is the snorkel still in place?

How recent is the fuel filter? If there is fuel system restriction causing retarded timing at high RPM, that can cause issues. Pinzgauers have a primary fuel filter under the body in addition to the main secondary filter on the engine, are both of them fresh? Tank pickup clean, tank vent OK, etc? Checked fuel inlet vacuum under load?

How does it start and run otherwise, basics like cam timing and valve clearance are all right on?
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83 764 D24T/M46 155k
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  #5  
Old 06-02-2017, 10:28 AM
718Pinz 718Pinz is offline
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Posts: 27
Default Photos of intake

Here is the short air run. Straight to the turbo, super short run to the IC and then about 1 foot to the intake manifold.




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  #6  
Old 06-02-2017, 06:26 PM
Cgingrich Cgingrich is offline
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Location: Illinois
Vehicle: 740
Posts: 13
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Wastegate stuck open possibility? Or something up with the boost controller?
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