Only getting 2lbs of boost

[95AWD6Bolt]

Just installed a 50 trim with an external tial wastegate. At first, it wouldnt boost at all, turned out I put the boost controller on backwards. When I fixed that today, I can now only get 2-3lbs of boost at wot. I just pulled the turbo off and the external wastegate is not stuck.
I did do a boost leak test and that turned out to be fine.

The only known problem that I have is that I have an exhaust leak in the flex section of my downpipe. Would that be the cause of the problem? Or could it be something else?

I am stuck and need help badly!

 

[dsmtalon2008]

Exhaust leak after your turbo would not cause this. To me it sounds like your wastegate is screwed up or you have an UNBELIEVABLY large pre-turbo exhaust leak.

 

[LiquidX]

Having a boost controller on wrong would cause you to have infinite boost, not no boost at all. The only way to not have boost in that sense would be if the wastegate was constantly open.

It does sound like a massive pre turbine exhaust leak or a boost leak. What psi did you test to, where did you perform the test at location wise and what method did you use to find your leaks?

 

[95AWD6Bolt]

15 psi and put the tester onto the turbo.
From there I just listened for audible leaks.

When I had the mbc turned up, it was leaking from there. Should that be?

How would I tell if the wastegate is messed up?

 

[XiKeiyaZI]

I don't know much about External Waste Setups, but I do know that a bad Pre-Turbo exhaust leak would cause this, like the others said above.

You might want to go ahead and check to make sure that your manifold it mated to the head correctly. Then check the Manifold to Turbo gasket and bolt torque specs. After this, go about checking the waste gate.

Does the car smell like gas from the engine bay, by chance?

 

[95AWD6Bolt]

No does not smell like gas.

Turbo is currently off the car, im going to go install it after this post.

Could it be the mbc? Its a turboxs bleeder style one that the previous owner put on. Im thinking that maybe ill try running off wg pressure and see if that helps.

 

[LiquidX]

Do your boost leak test again. Test it to 25psi and use a spray bottle of soap and water and look for bubbles. Not all leaks are audible. Spray everything that sees positive and negative air, feel around vacuum lines (cracks) sprat the throttle body down good and rotate the throttle plate (shaft seals and BISS), intake manifold gasket, EGR, etc.

Post those results.

 

[1slo1g]

Check to make sure your 50trim is set up for a external gate. if you removed the internal gate make sure you weld it up or you will not be able to create any boost or very little.

 

[crash89]

Check to make sure your 50trim is set up for a external gate. if you removed the internal gate make sure you weld it up or you will not be able to create any boost or very little.

He didnt say where he was running the wastegate from. If hes running it off the 02 housing then he should leave it open, if off the manifold then yes it would be best to weld it shut.

Where are you running your wastegate from? I would suggest to eliminate the boost controller for the time being (for test purposes).

 

[KyDSM]

I think autozone has a leak down tester you can rent/buy from them. Or get a spray bottle with soapy water. Then search til your eyes bleed. Sounds like a boost leak or a bummed turbo. Lets hope leak!

 

[95AWD6Bolt]

Ex WG is run off of the o2 housing. Yes, the flapper has been removed and the hole where the flapper arm was was welded shut.
The turbo better be ok, it was just rebuilt and it has idled for about 5 minutes and been driven less than 2 miles on test runs.

 

[1slo1g]

What I was referring to was whether or not it is divide like this picture.

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or if it was un-divided like this one

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[gvr4550]

take the mbc off
check the wastegate spring it could be weak and opening to easily
are you runing an external wastegate dump?

 

[95AWD6Bolt]

It is divided.

Recurculated via fp o2 housing.

 

[LiquidX]

Re do the test like I said and use a spray bottle of soapy water...

 

[SlowDSM_GSX2g]

just a simple question?

you are acelerating the car when neutral or you are running it?
you need to do a 2nd or/and 3rd pull to see if it is making boost

when I instaled my 60 trim didn't made any boost on neutral just 0, but i did a 3rd pull and it push 30 psi

 

[johnmarines]

You can always make a block off plate to cover the wastegate hole to eliminate a bad wg. Just make sure you take it easy because this will cause infinate boost and will blow your motor.

 

[LiquidX]

You can always make a block off plate to cover the wastegate hole to eliminate a bad wg. Just make sure you take it easy because this will cause infinate boost and will blow your motor.

Terrible advice..

You can do the same diagnostic by taking off the vacuum line to the WG. If the spring is light enough it will open on it's own too to prevent excessive boosting.

He needs to redo his boost leak test with 25psi and soapy water before anything else is done. I only say 25psi because you should always test to above what you will be running and don't come in here and say it will be damaging as it will not be damaging to the motor.

25psi while boosting is different than 25psi cold air pressure as there isn't a chance for detonation.

 

[95AWD6Bolt]

Re do the test like I said and use a spray bottle of soapy water...

Did exactly what you said and WOW, WHAT a difference. Here is a list of the leaks:

Throttle Body(Replaced Gasket)
Biss Screw(Unfixed-Gasket Ordered)
BOV(Mostly Fixed-Pinhole leak Now)
Massive IC Leak on a 90 Degree bend...fixed)


Now its holding 20 psi at the blt gauge and it says 16psi on my boost gauge.

Didnt get a chance to drive the car yet.

 

[crash89]

Good to hear! Now get out there n get boostin!!!

Just keep it safe.

 

[LiquidX]

It's amazing on the things that you cannot find one way but do it another way and you have a solved mystery.

 

[95AWD6Bolt]

It's amazing on the things that you cannot find one way but do it another way and you have a solved mystery.

It's crazy. Thanks for passing the knowledge along!

 

[smcasey1]

my buddie had a 7lb boost leak coming from his intercooler pipes, so maybe give tht a run over

 

[XiKeiyaZI]

my buddie had a 7lb boost leak coming from his intercooler pipes, so maybe give tht a run over

I believe this was already resolved when the OP decided to finally perform a proper boost leak test... which would also test your Intercooler piping for potential leaks. Also, you can't exactly measure how much a single leak will decrease your PSI. Saying that a pinhole causes a 2LBS leak would be incorrect.

Just throwing that in there.

 

[robertseber]

glad you got it worked out