ok i know there have been many threads on this and i keep asking questions however my problem still arises and i dont know wat to say

did some testing today

everything stock, tcv connected to WG, INTAKE ,BOTTOM OF TURBO - 5-6 PSI

added MBC connected to the mix set at 13 psi( off another 850) - 5-6 PSI

completely removed WG - 1O-11 PSI



so whats next? i cant figure it out at all why am i not reaching boost levels
its as if adding an MBC did absolutly nothing aswell

does anybody know of anything that can help? i've honestly ran out of ideas as to what it could be! buddy of mine was thinkign WG and its set weirdly and stays open, thoughts?

 

Here is a diagram that was posted on another thread. The MBC will go between the green and the yellow vacuum lines. Be sure you check the condition of your lines.

https://volvoforums.com/forum/attach...7&d=1267663784

If you really want to test your turbo, remove the yellow line from the turbo.

**CAUTION** drive your car WITH A BOOST GAUGE. You be very careful as you are the wastegate. You can feather your throttle and watch your boost rise. Your 15G should be able to hit over 20psi but you will probably hit fuel cut off before then. This test is only to see if your turbo can boost. YOU must be ATTENTIVE and CAREFUL.

As for your MBC. Dont rely on another person settings. After testing if your turbo can boost, install it and begin to adjust it.

I get the impression you are trying to do this without a gauge. Not a wise thing to do. Protect your car, get one.

If nothing changes after these suggestions then I would look at the internal blowoff valve as being possibly weak or torn.

 

i coulda sworn everything you are telling me to do i have already tried...

the MBC was installed that way

i disconnected my WG and only reached 10 pounds

i mean how are u seeing that i'm TELLING you what pound of boost i have? obviously i have a boost gauge

is there and easy way to remove the CBV from the turbo with it ON the car?

 

Sounds like you have a boost leak somewhere.

 

but ive checked every line i have my silicone IC hoses r coming in soon but lets play it out as if its not those hoses

 

Then I would check the CBV. It is a pain to get off but you can get it off.

 

[quote=s_moneh;210507]
i mean how are u seeing that i'm TELLING you what pound of boost i have? obviously i have a boost gauge[quote]

Now that is an excellent point and something I missed, sorry.

You only have two options left and your on them both. A boost leak or a problem with the CBV.

 

Can i get it off from the top of the turbo? Amd when i do get it off what am i looking for?

Could the WG be a culprit? Maybe she stays open?

 

The CBV is on the top but close to the engine with stuff in the way. Hard to get to but you can get to it. Its only held on by three bolts. From what I understand the diaphragms can tear and the springs can become weak. IPD offers a replacement. If the spring is weak I dont know if there is really any way to test that without equipment to do so.

 

my plan is to blank out thge cbv anyway but lets see wat happens!

 

Hopefully you find something when you get in there.

 

so instead of buying the springs can i just get a block off plate made? i read a couple places you can. just trying to figure out for sure if i can do it and which is the best way to go. i only plan on doing minor modding such as exhaust/intake and upping the boost some around 13psi. what do you guys think?

 

You cannot bypass it unless you are going to run a BOV.

 

yeah i will definatly be picking up a BOV. ive been doing alot of research on alot of stuff on here.