Hey guys
Just installed mbc on my 96 850 turbo, didn't get aftermarket boost gage yet ,but i figured i'll keep the boost low to be safe until gage arrives. But to my surprise, seems like mbc isn't doing anything. No matter how many times i turn the **** on the mbc, no boost increase and the car feels the same everytime. I even used all new hoses to hook it up, to eliminate leaks. I am also pretty sure i installed it right way (wastegate to the side of mbc and turbo hose to the bottom). Don't know what to do. Can somebody point me in the right direction?
Thank you so much.

 

What do you mean turbo hose bottom?

You connect the MBC between the compressor hose from the bottom of the turbo to the wastegate.

 

Sorry about that Tech, i meant compressor hose connected to the bottom of mbc and wastegate hose to the side of mbc.

 

Ok maybe there is something wrong.
Try this BUT ONLY TEMP FOR TESTING!! disconnect the hose to the wastegate and test drive and see if it wakes up. If it does either the MBC is installed wrong like maybe the hoses need to be swapped or something is wrong with the turbo or intercooler hoses.

 

will test drive it with wastegate hose disconnected right now, Tech you are the best.

 

Let me know how it goes. That will make it run at Full Boost. If you hit 15.5 lbs you will hit fuel cutoff.

 

wow, thats what i'm talking about. totally different car. boosted much higher but didn't reach fuel cut off. what do i do now?

 

Either the MBC isn't working correctly or the hoses are connected wrong.
Does the directions on the MBC you have say to connect the compressor side to the bottom on the MBC?

 

says, connect a hose from wastegate actuator to the side of BC and connect presure line from intake manifold to the bottom of bc. thats it.

 

Then it should work unless something is wrong with it.
Since the stock boost guage works then I know the turbo is boosting. Also the last test drive shows that as well.

What brand is it?

The compressor hose did not blow off the turbo did it?

 

compressor hose is good , still in it's place. mbc, no brand, got it from ebay for $15. so at this point the mbc isn't working properly, right? do i have to get new one or is this one still fixible?

 

I would open it up and check the ball and spring. Then put it back together and try it again. Remember the more you screw it in the more boost you get. The looser it is the less boost you get.

 

Aight, will check out mbc's internals and do more test drives. will let you know what happens. again, Tech thank you so much. have a great weekend (whatever is left of it).

 

Your welcome I am trying to enjoy it. LOL

 

i think i figured out what was wrong with it, the compression spring was getting stuck inside mbc. way too thin in diameter for the inside of the unit. i found just right size spring at local home depot yesterday, and now it seems to be working, transimission downshifts better and the car feels much more aggressive. thanks for your help Tech.
Regards.

 

Your welcome glad you got it fixed!