i have a hallman mbc on my car right now during tuning it was reading a steady 8 off the mapsensor. i installed a boost gauge first one only read to 4 full throttle. i checked for boost leaks didnt find anything so i turned it a few times still read 4. took the vacum off the wg and ran open wg it went to 4 car shut off(boost cut is at 9). used 2 different boost gauges (greddy and a sunpro) and both read at 7 i kept turning it and it still stays at 7. i then pulled the vacum off the wg again and it shot to 9 and cut off so i kno both boost gauges work fine. now the mbc is turned all the way down and its stuck @ 7 wont go any higher. has anyone had problems with the hallman mbc? i am going to try another mbc tom(turbo xs) see if that will help a lil bit. i rechecked the vaccumes and checked again for boost leaks, nothing. everythign seems to be in working order. wat else can i check?
thanks
cliff

 

sounds like air is bleeding off before the MAP sensor which is not good. Where do you have this MBC hooked up in between?