Turbo actuator boost to high.

[choppyspin]

I have a 4agze in my ae86. I have removed the supercharger and now has a t28 with a internal wastegate.I need to get tuned becuase Im using a haltech ecu now and the turbo set up is new. The person who I'm getting to tune it said he would like to have it running around 10 psi and then wind it up with a controller slowly to a safe boost/tune. My problem is I can't get the boost lower then 15psi. I got a new actuator and tested it before installing it which was opening at 5psi fully open at 10psi. But installed it still runs to 15psi i adjusted the rod but no difference. Dose anyone know why this could be or dose anyone know of any other way to lower boost?

cheers Nathan