Hey guys, I'm new to the forum and I have serious question: last year my evo 8 started to only build 12psi (factory is 19psi) and over the past year I have spent about $1,200-$2,000 on trying to fix the problem. And this is what I've done.
- new intercooler piping
- new intercooler
- new bov
- new wastegate actuator (from factory)
- new boost controller solenoid (from factory)
- new gauges (innovate)
- new hotside of turbo
- all new hoses that has to do anything with boost or vacuum
- all new couplers
- AND I EVEN BOUGHT A MBC AND I CAN TURN IT TILL ME HANDS GET NUMB AND STILL DOESN'T BOOST OVER 12 PSI.

So I need some advice and help on how to fix it. And please be mature about this (not start talking crap or stupid stuff), and please if you don't even work on your own car then don't post cause it's pointless. Again Thanks for you insight

 

I would start with the usual places - Boost leaks? Especially at the throttle body. Did you do a boost leak test? Next is shaft play in the turbo? Is there any scoring on the inside of the intake of the turbo from the wheel rubbing? How about tuning? Did you (or anyone) do anything to your tune? Especially the "boost" tables (wdgc, etc..)?

 

fuel injector seals, i had a wicked bad leak at my fuel injetor seats and a little one at my throttle body seals.

do a boost leak test and use soapy water to spray at all points where a potential leak could happen.

 

http://www.cobbtuning.com/Technical-...es-s/70672.htm

read this it really sounds like a boost leak to me, specially if you replaced all that stuff

 

I did a boost leak test and i found nothing, i took my soapy water and sprayed everything and didn't see a thing.
When i had the turbo off the change the hot side I took it to turbo auto in nashville and the checked it out and found no scaring, no shaft play, etc.

For as tuning, there is no aftermarket tune on the car, it's on the factory tune/ecu. AND KEEP IN MIND THE CAR IS A 2003 AND ONLY HAS 34K MILES ON IT

 

Dont forget to check your Jpipe. Mine was leaking and wouldnt build past 15psi! My gasket was completely gone, where the leak was. GL

 

And I also replaced the EGR and the EGR plate also.
But I will replace the injector seals just to say i did

 

and exhaust leak at you manifold? head to manifold or manifold to turbo? maybe a smoke test to check your exhaust system

 

I've gotten a new turbo manifold and i replaced every gasket... to the head, turbo outlet, cat, and where the turbo hooks to the manifold. I'm going to the parts store right now and getting the injector seals and throttle body gasket and i will write back and till you guys if that worked

 

do you have the stock cat? maybe it's clogged, that would cause your car not to boost properly.

 

also, check for a loose hose behind the intake manifold, it's the egr hose that usually pops and nobody notices because it's back there.

 

cats aftermarket.. has 10k miles on it
alright so i just ordered...
- injector seal set top and bottom
- throttle body gasket
- J pipe gasket
- throttle body shaft seal (that connects the throttle plate to the intake manifold)

So they should get here Wednesday and I'll install all of it and hope that one of those things helps. And while I have the throttle body off I'll check the egr hose to see if it popped off like you mentioned.

 

When you did your boost leak test what did you pressurize the system to? Also might want to hook up a smoke machine and push some smoke through it see if that shows anything. Seems like a combo of thingss. Do you throw any codes of any sort? Can you do some logging?

 

I'm not throwing any codes. No I don't have the software to do any logging and I don't know anybody around Nashville that does either

 

Even if you have those leaks, that shouldn't stop your car from boosting to 19psi.
You have to get a diagram of how the OEM hoses from the boost control solenoid are installed, and make sure you have the FACTORY hoses, because there's some restrictors in there, if you don't have them installed, then there's your problem.