hallman mbc cant turn bost down!!

[eric91gst]

ok heres the deal. Its hooked up right and everything and used to work before. It just started acting up in the past day or so for some reason. It always wants to boost past 15 and get into the 20 psi range. It seemed that this started to happen ever since I loosened the spring on my greddy type rs bov, but this wouldnt have anything to do with the boost issue I presume. I took the mbc off and just ran a hose to the actuator and I was boosting at about 9-10, so it has to be the mbc. Whats going on?
-thanks

 

[No_Skillz]

Can you tell if it's really boosting that high or if it's boost creep? How are the lines for the MBC hooked up?

 

[TiradoCC]

you might have the boost controller hooked up wrong

 

[kenamond]

Do you have your MBC T-ed into the BOV vaccuum line? Or is it straight from the compressor outlet to the MBC to the WGA?

You should be able to loosen the MBC all the way and blow through the end that is supposed to go to the compressor outlet and have it leak. As you tighten it, you should reach a point where you can't blow through it any more.

 

[eric91gst]

nvm guys fixed the problem. It was the spring in the mbc. I took it out and shrunk it down in a vise. I guess it was too stiff somehow and creating the effect of having the knob screwed in a lot on the spring.