i have a 98 gst 5 speed. i have a turo xs mbc hooked up the right way. im 110% sure it is correct. ive had a couple other people look at it recently and it is right. i cant get anymore then 14 lbs out of the stock turbo and thats peak boost. usually runs 13psi. could my waste gate be sticking in one place? it vaccums at 19 psi at idle sometimes 20. which is normal. everything seems fine. boost wont go up though

 

must have a boost leak somewhere, find it

 

Your wastegate could also be opening due to the increased amount of pressure. In other words, the exhaust could be rushing passed the flapper. The stock wastegate actuator is good up to 10 psi and the boost controller is really just an adjustable vacuum valve to aid the actuator.
But Sk8 is right, look for boost leaks with a boost leak tester.

 

the only place it could be a boost leak is the mbc. before i dosconnect the stock lines it wokred perfect.

 

it vaccumed perfectly at 20 at idle

 

ok i have my mbc taken off. im trying to see if my mbc is faulty. if i blow threw it shouldnt air some out the other end?

 

ok never mind i got it to work. i blew threw it and it stops when u blow really hard. ha sounds kinda G*y

 

ok that didnt work. i shorteneed the lines as much as i could without makin any tight bends. butttt i did find out something that could be leaking. on my stock bov the elbow that goes from bov to intake has a small slice in it. and on the end that clamps to bov is split about a half inch down. would that cause me not to push anymore then 14 lbs. but not matter how far i turn the mbc down(ppsi wise) it doesnt go down. nor go up still. wouldnt it atleast go down?

 

Let's backtrack to be sure that we are all on the same page, ok. This is the MBC that you have, correct? Turbo XS (standard).

 

...and you used these instructions when installing it, correct?
http://www.turboxs.com/uploaded_images/521.pdf