mbc not working properly

raint5 · Post by **raint5** » 16 Apr 2010, 19:19

so i installed a mbc today, when i took it out and tried tuning it, i couldnt get more than about 3 psi out of it, i continued to adjust it up more and more, no result, i finally turned it down all the way, and managed to get approx the stock 9psi, any suggestions?

raint5 · Post by **raint5** » 19 Apr 2010, 18:39

nobody knows anything about this???

Post by **jblackburn** » 19 Apr 2010, 22:01

Most often a car can't build boost up because one of the 3 vacuum lines to the turbo is cracked away or missing. Thus, the wastegate will dump out all of the boost as a failsafe.

Post by **matthew1** » 20 Apr 2010, 10:45

Sorry, never added an mbc to my 850 to address specifics, but is your car stage 0?

Post by **JDS60R** » 20 Apr 2010, 11:04

Tell us which MBC you are using and how you hooked it up. The Volvos use a three hose system and not a two hose system like most manual boost controlers. You may have hooked it up wrong. Without knowing exactly what you did , and everything that you did , we are unable to diagnose the situation.

Just the fact sir -just the facts

raint5 · Post by **raint5** » 26 Apr 2010, 14:27

ok, now i think about it i didnt hook up the line that goes from the stock boost controller to the maf, how do i need to do this? and is that most likley the problem?

raint5 · Post by **raint5** » 26 Apr 2010, 18:48

so it just crossed my mind a couple minutes ago after a little thought, that even if the problem is that the boost line to the maf isnt hooked up, that still doesnt explain why the boost would increase when the controller is turned all the way down, just a thought.