some things to check...
First thanks for your purchase!
Some things to check are that you have the MBC installed only between the wastgate actuator and either the compressor or a boost source after the TB. You don't want any vacuum/boost connections from the MBC to any modified boost source (e.g. after the solenoids.) Also, make sure that the port exiting the MBC (smallest ID) is connected toward the wastegate actuator. The opposing end is of course connected to a boost source. Also, remember that one full revolution is only .25+- lbs of adjustment. You may have to spin it a bit to get a huge change.
Finally, do you have a BOV or BOV upgrade to the vehicle that is still connected to a modded boost lead? If that is so it may be opening and releasing any additional pressure beyond the factory preset.
Let us know how we can help further! We want you to be happy with the performance from your purchase.
503-643-4677 xt 203