Can't Boost Past 15psi????

[krazywhitboy]

First off, here are my mods.

Evo3b16g
550's
190lph
Safc
o2 dump
K&n filter
hard intake pipe
1g bov
bleeder valve type MBC
DataLogger (pocketlogger)

My car has been down for 2 months due to a blown turbo. I finally got it up and running with evo3b16g and supporting mods for it. My MBC is a homemade type (bleeder valve) that opens to add boost, closes to subtract. For some reason, i cannot boost past 15psi?? With the mbc closed, i hit 9psi. then i open it all the way, it only hits 15psi. I checked for boost leaks, and had one at the jpipe. Fixed the leak, still having the same problem. I know the WG on the turbo itself is good....I'm out of ideas....

I also believe that my front o2 sensor is shot. The short trim and long trims on my logger do not change at ALL when i adjust the SAFC, nor do the o2 volts fluctuate. The volts stay at .02, and do NOT change. My short term and long terms (on safc) stay stuck at 12% (short) and 17% (long). I don't know if this could possibly be related in any way to my boost problem?

Any help/ideas/tips would be much appreciated....

 

[IHeartTurbo]

Yes, you need a new o2. Or the wires are cut/frayed/####ed.

 

[krazywhitboy]

Yes, you need a new o2. Or the wires are cut/frayed/####ed.

ok....any ideas on the boost problem?

 

[oldman]

ok....any ideas on the boost problem?

You're probably surpassing the maximum amount of air the valve is able to bleed off, get a ball and spring type mbc and you should be fine.