Hey, i have some issues with my ST225.
It all started with slowly down boosting (from 4/4 to 0/4 of boost.
It gave full boost, after 50 miles just only 3/4, then 2/4 etc to 0 boost.
The needle of boost gauge doesn't even move a bit, only when i do full throtle and then take off throtle pedal, but Its really a bit (like 1/6 of boost)
Im mad of it, becouse it have power like some 1.2htp 40kw
I changed the boost solenoid, MAF, MAP and even with the new turbocharger, it's still the same.
The engine RPM goes max around 5-6k, and sometimes doesn't go even on 4k.

When i take off the turbocharger pipe to intercooler, it seems like turbo works well (feel that air in my face really good)
Only what doesn't work on that turbo Is Wastegate, but it doesn't work, becouse that little pipes from turbocharger to Solenoid valve doesn't have any air in them, only a bit at full throtle, but i can't tell why...
Do you guys have some advice?
Thanks for your time. Hope someone will know.

 

Check your vac pipes in round your turbo and boost control solenoid they can crack if they are still the original ones that were on from factory