Ive replaced every dry rotted or cracked vacuum line possible and still no boost.
My boost gauge reads vacuum but when under load the gauge barely zeros out.

 

Have you specifically replaced the short vacuum lines on the wastegate actuator?

Maybe unclip the arm of the actuator from the wastegate lever. See if it moves back and forth easily. If the wastegate is the issue then it should be stuck in the open position.

You may also want to take off the large intake hose from the turbo. reach into the turbo and spin the blades to see that it is not locked up tight.

 

Will do. Thanks, I'll see how things go

 

Did it used to boost? Even though the gauge reads zero, does it feel like it's boosting at full throttle?

 

It definitly feels like its boosting

 

Could it be a faulty gauge?

 

Hook up an aftermarket boost gauge & check it that way.

 

the factory gauge reads from a little electronic signal. The sender unit could be bad... maybe

 

I you go from vacuum to 0 or slight positive pressure you got boost. The factory gage is notorious for being off. You can get a decent boost gage from Harbor Freight for $20 that will actually show you what is going on.