Is my MBC setup FUBAR?

[awild]

Ok I've been trying to find out why I'm getting fuel cut. Car came without a boost gauge but mbc. Dangerous not knowing what you're running on an EVO III 16g...more dangerous to come and find out it's basically running 20psi plus.

*Installed gauge today. Drove car. Boost is way high and shows no signs of being controlled at all. MBC adjustments do nothing at all. Back the screw all the way out...nothing but super high boost still. The screw was originally all the way in (thus maxing the mbc's setting to the highest possible...another not so good thing to find).

So here's my MBC's routing. Is it f'd up or am I crazy? Should I change how the previous owner has it routed and hope that's the cause or is it likely the whole MBC is just crap.

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[nfernotalon]

Yes, you dont want shavings anywhere, make sure you clean it after.

 

[kenamond]

Tap the j-pipe like mentioned, then line straight from j-pipe to MBC to WGA nipple.
One vaccuum line (go buy a new piece) from BOV to intake manifold (IM)...and I think ECI means electrically controlled injection or some shit.
And you may still boost to 20psi. If you have an upgraded exhaust, the evo3 turbo is notorious for boost creep. If you don't know what that is, search and you'll find out more than you ever wanted to know.

 

[awild]

^^^ Thanks. I do know about boost creep and will be tickled if I dont have it considering the apexi N1 exhaust. Looks like I got my work cut out for me tomorrow running around town getting small stuff and rerouting.

 

[nfernotalon]

I wouldnt worry too much about boost creep because of the exhaust, I installed a 3in catback and made no boost creep at all, but yours might act different..

 

[awild]

I wouldnt worry too much about boost creep because of the exhaust, I installed a 3in catback and made no boost creep at all, but yours might act different..

A 14b or 13g probably wouldnt creep...but I'm running an EvoIII 16g so I'm a little less lucky there in terms of creeping.

 

[nfernotalon]

Oh yes, forgot you had a 16g. Hopefully when I get mine it wont..

 

[awild]

As expected there was a damn blizzard today so I'm not going to brave the 40mph sideways snow blasting me in the face as I attempt this.

 

[eagletalonjohn]

What is ECI (either I've never heard of it or just drawing a big blank)?

+1. what is a eci?

 

[snowborder714]

+1. what is a eci?

Look at the picture in post #14 (specifically the intake manifold). Read post #27.

 

[awild]

+1. what is a eci?

Lol theres a picture of it in your avatar.

 

[nfernotalon]

Get that thing fixed?

 

[awild]

Get that thing fixed?

No, I've only got a 3 sided carport in my current apartment. And its 20F out, 30mph winds, and expecting up to 15" of snow today....Lets just say that the Jeep is the DD for awhile.

 

[kenamond]

Lets just say that the Jeep is the DD for awhile.

+AWD+snow=

 

[awild]

+AWD+snow=

Haha, I've had awd dsm's and an awd Stealth in the winter before....when the snow is over the front bumper you aint moving.

 

[kenamond]

Haha, I've had awd dsm's and an awd Stealth in the winter before....when the snow is over the front bumper you aint moving.

I've gone up fairly steep hills in 18" powder no problem...except the snow covered my headlights and it was night, so it was a bit dark...and if I went too fast, the powder flowed over the hood and completely blocked my view...but it was all good in the end.

 

[awild]

Welp I think I found the major issue with my MBC...there's no ball bearings in there. Just a spring. Is there a quick fix for this or should I just buy a new mbc?

 

[snowborder714]

Just go to your local hardware store and buy a ball bearing.

See this as a reference:
http://www.geocities.com/chmwatson/FAQs/mbc.html

 

[awild]

EDIT - Thanks for that link^


Sorry, newb here. Especially considering the fact that I'm "fixing" the stupid last owners issues. Halfway home on that.

 

[snowborder714]

What type of MBC do you have or is it a homemade one? Could you post a picture?

Almost all of the ones I've seen only use one.

 

[awild]

What type of MBC do you have or is it a homemade one? Could you post a picture?

Almost all of the ones I've seen only use one.

Appears to be a homebrew. And upon third inspection it does have a ball bearing. It was lodged so far down and so snug that it wouldnt budge. So I took the mbc off and started smacking it to get the bearing to move. Maybe this will fix the non-limited boost.

http://www.uploadfx.com/imagebox_1202429956_r22.jpg

 

[snowborder714]

Hopefully it does. If not, I'd say go out and build one according to that link I posted above. It's only about $10 for all the parts and works fine.

 

[awild]

Just went and ran the car again. It was boosting up past 25psi (for a split second until i saw how high it would go) when the steel ball was stuck. Somewhat of an improvement now as it's down to 22psi with zero tension on the mbc spring. Seems a little excessive for what should be stock boost. I'll go build myself a new mbc and see how that treats me.

 

[nfernotalon]

Thats good but you still need to hook it up the way we told you..

 

[awild]

Thats good but you still need to hook it up the way we told you..

Oh I know...oddly enough the link to build your own MBC shows to hook it up the way my current setup is hooked up.

I might try stretching the spring in my mbc before I build a new one. It sits 6 threads into the mbc which seems kinda far.

 

[snowborder714]

Please don't follow the image in that link!!!!

It is not correct as you should have nothing tapped into your bov vacuum line. Connect the bottom of the mbc to your source (j pipe, compressor housing, etc.) and the side to your wastegate nipple.