Hi All new to this Forum hope I'm in the right section ???

Got a Turbo Boost Issue with my 2012 ZD30 CRD this problem started six months ago where l went away turned the car off restarted and only boosting at 4psi two days later it cleared back to normal 13psi for six months and now same problem.
When l bypass the Vacuum Controller and hook the Actuator directly to the vacuum pump l get 10psi.
I have replaced the following

* All vacuum lines
* Actuator
* Boost Sensor
* MAF Sensor
* 3inch Exhaust
* New Turbo

I have even try bypassing the vacuum system with a Diesel Smart 20psi Pressure Actuator with boost pressure direct from intercooler and only got 2-4psi

Does anyone know a good Patrol mechanic on the Gold Coast ? already had it to two mechanics and they couldn't find anything

Any help would be much appreciated

Cheers Simon