Throttle/turbo not kicking in properly

Hi there wondering if anyone can help having trouble with turbo not kicking in had it checked at Sedox performance and turbo checks out ok maf ok egr checked throttle body working fine then they checked the intake manifold vacuum actuator which think he said opens your flaps not sure though so tested it and was shot opened it up big hole in the diaphragm so wanting to no if anyone has had the same issues and can it be done DIY May not fix the issue but praying it does update the new diaphragm never worked still bad throttle up to 1700 then picks up but still not as blistering as it was can anybody help me please thanks