high pressure actuator switch...

this actuator switch... how does this work? from oil pressure or turbo pressure? i ask as i am trouble shooting and i think my HP turbo is crapping out. lags on starting with acceleration, trouble shifting gears on the low end, irratic shifting. whining noise on shifts when rpm drops. I think maybe this actuator is seized... just wondering how i can test this. Of course i will remove the hose for an inspection and inspect the high pressure turbo at well. Also, do you recommend this as an easy re and re to replace HP turbo or are there many other factors in place which i could cause more damage by just replacing the HP turbo. Any help is appreciated for this guy with some mechanical skills and intelligence.

 

i answered my question myself here, step by step... the boosts pressure 26-28psi activates the actuator. The waste gate freely moved, which lead me to believe that the actuator was siezed or the membrane was ruptured. This alone almost nearly removed all whining/whistling while shifting gears. there is still some lag on starting out and a lot less issues shifting in 2nd or 3rd to reshift in same gear. I hooked up a pressure gauge to the fuel and have 69psi. I changed fuel filters and added a tiny washer to the transfer pump side spring, but it looks like this won't bring it up to the minimum 75psi rating for the transfer pump. Before I spend money on the return fuel regulator on the base fuel filter or transfer pump itself, any other tips on how to increase the PSI on the fuel system? I did a calculation on MPG and it is at 1.19 mpg... this seems really low pulling 60,000lbs loads locally.