ok i went through all the vaccum lines,gaskets and all the boots on the piping and i still can not figure out why i can not boost more then 4-5 psi. i was boosting 7lbs. originaly but then the turbo manifold gasket blew i replaced it with a way better one and it is sealed good but i still cannot get my 7lbs back no mateer what i do. if i put a manual boost controller on it do you think that will be able to crank it back up or what because as of now i have no control at all on it.

 

internal or external wastegate? if internal wastegate check the wastegate flap and make sure its sealing. also check the wastegate actuator rod length if its adjustable. if external wastegate check the sealing ring on the wastegate plunger to make sure its sealing or if its even there. a lot of people forget to put them on.