Originally Posted by
juffer
i had the exact problem a few years ago. it was the wastegate "penny" in the elbow had fallen off
I had the same sort of problem only weeks ago... found out to the the actuator was holding the wastegate open. When its off boost the actuator should be holding the wastegate (penny) shut, if it not its letting the boost out, thus no boost
Try it mate, i had this problem for ages and was a simple fix.