OMG.. New setup, still can't boost more than 10psi

[trapspeed]

I couldn't boost higher than 10psi on my 16g. The wastegate seemed to be fine and I thought it was the boost controller.

So now I have a diff turbo (TO4B V-trim) and a new MBC and I still can't boost higher than 10psi. WTF? I max out the MBC (Turbonetics) and it still wont go higher than 10. Need help!

 

[Stealth02]

Have you checked your intercooler pipes, intercooler, clamps, vacuum hoses, 02 manifold gasket, exhaust manifold gasket, boost guage, proper boost controller intallation (lines for the boost controller)?

These are just a few to start, let us know what your methods of troubleshooting have been so far so we can rule those out and pin point the root cause of the issue.

 

[trapspeed]

I've checked the IC and all the piping, all of which seems to be good. It's strange, sometimes the turbo over boosts, 20++ and sometimes it won't go past 10. And when I overboost I get this real fast sputtering once it goes over 16psi.

 

[Stealth02]

So with that checked, here are some more questions to help you out.

- Are both of these turbos internally gated?
- Or are you using an external set up and just swapping the turbos out?
- I noticed you mentioned MBC, but I just wanted to clarify that you do have
a manual boost controller.
- Are you sure your bov is adjusted correctly and/or is not having issues holding and
releasing the pressurized air?

 

[ddavisaf]

Check for Boost Leaks.

 

[trapspeed]

They are both internally gated.
Yes, I do have a Manual Boost Controller.
I will recheck the BOV.

 

[laserspeeddemon]

Man, this gets old
BOOST LEAK!!!!!

 

[trapspeed]

A boost leak can cause the boost to spike like that also?

 

[laserspeeddemon]

depends on the nature of the leak, if you are leaking from the signal line to the MBC, then yes. PCV Valves sometimes go in and out right before they fail, etc.

 

[TooFastTooG]

Hey, just thought I would add to this since I experienced somthing similar.

I had a manual boost controller and no matter how high I turned it up I couldnt get past 10 psi, in the end it ended up being my leaky bov(stock 2nd gen). Replaced it with a 1g bov and problem solved. Runs 16psi no problem now.

 

[1gnasty]

check some of the old t netics boost controlers wont past 10 psi thatall they are good for
chek on the bottom i say it there

 

[trapspeed]

Appreciate all the help guys.

The dude at the shop said it would exceed 20+ psi for sure.

 

[Stealth02]

Man, this gets old
BOOST LEAK!!!!!

I was thinking the same thing from the start, but he said he already checked it. There is something wrong with his piping, intercooler, bov, vacuum lines or intake related component. I just find it hard that two different turbos and two different mbc are behaving the same way in the same environment. I am leaning towards the problem being somewhere elsewhere than the turbos and mbc's. It is possible for both combinations to go bad, but not likely.

Where you running more than 10 psi before all this? If so, what changes did you perform on the car between then and the time your issue started?

 

[ddavisaf]

Hold long did you hold 20 psi during your boost leak test?