Ok guys, as you all know i made a thread about having boost creep, not only that but part of the problem is that everytime i make wot passes and the boost spikes real high, i get out and turn it down like 3-4 times and it still wont go down, ill make another pass and then the boost is really low! It seems that adjusting boost levels are NOT responding the way it should be. I have asked a few ppl for their ooinions and the first thing they say is "its your boost controller".. Im assuming its getting stuck inside, resulting in not being able to adjust it immediately like before. Sometimes im getting real high 24-25 psi in 4th, sometimes in 3rd resulting in fuel cut. What do you guys think about this problem? Is it the mbc?

 

Yes, it could be the UNOS. Many people have had this problem. You need to open it up, clean it out and apply some synthetic bearing grase to the bearing and spring.

BTW, do you still have the aftermarket o2 housing on?

 

Yes its still on currently

 

There have been a number of reported problems with the MBC. That said, when setup and working properly they seem to be quite good with the VIII.

I have a IX with an MBC and am not completely sold on the setup -- I would rather have the ECU and EBC do the work.....

 

Clean and lube the UNOS. If that doesn't work, I'll bet "the farm" its your o2 housing. I know its a beatch to remove, but just do it.

 

Honestly i think its the forge mbc, think about it, changing the boost levels up or down dont respond immediately, so theres something wrong with it, if its not responding like it should

 

Try isolating the problem , take off the Forge mbc and run the vac stright to the WGA . You should then be running -/+12psi (wga pressure) if it "Creeps" after that is not the MBC . Then you can start looking somewhere else

This weekend I saw a evo with the same mods as me expt he had a stock IC act very diffrent than my car .
My psi would peak @22 and drop to 21
His evo would go up to 21@ 4000 and then "creep" up to 23-24psi at 7000

We both had 272's , intakes , uicp ,3"tb , hallman mbc , on leaks and a "ebay" O2 housing....

 

I think its the mbc bc it only does it in cold weather. I have heard of the Forge mbc having the spring or ball getting stuck at cold weather. So this is another reason why i think part me not being able to lower the boost after a few times leads to the mbc

 

How "cold" does it get in Orlando? With a big temperature swing up here in CT of around 50 degrees I'll see a change in boost of roughly 0.1 bar (about 1.5 psi), this is with the Forge MBC and it still holds like a rock and I have the Ebay O2 but only the 9.8 housing.

I'm hearing more people attach this problem to the Ebay O2 housings than any MBC. A couple people already pointed that out to you in your other thread.

There also seems to be mostly people with ported mani's/ 10.5 housings that are having these issues and more on 05's and 06's.

 

Part of the problem is that sometimes if i adjust the boost down with the mbc it doesnt take effect immediately, usually takes a few times turn it and do a few wot passes to see the boost go down, but then again it goes down too low

 

ill sell you my ams it has the harder spring that can hold up to 31 psi.

 

The problem isnt that it doenst hold boost, its giving me crazy spikes and its not responding when i turn it down after a few times, it takes a while b4 it actually goes down.

 

Are you useing the rubber lines that came with the kit or are you reuseing the stock ones.

 

Why dont you just have Jon datalog your car so you can find out whats really going on with your car. Now with this problem that i had before i tune or race the car im going to datalog the car to make sure nothing wrong. Its better then asking everyone whats going on your just going to drive yourself crazy trying to find out whats going on with this you can just get the facts.

 

Everything worked fine before the o2 housing install, correct? If so why dont you want to believe it's the o2 housing? Afterall you saw how many others are experienicing issues with theres.