engine cutout

[Grizz]

Having issues with my stock 87 GN, run the engine up to about 3500 rpms and engine starts to cut out, sputters, turbo then releases through blow off valve.
I have tried,
New MAF sensor, no change
upgraded to a Walbro 255, getting consistant 45 psi up to cutout. no change
car was running choppy at idle, now it seems to smooth out some then when it hits 3500 or so I get the cut out. It almost acts like a governor on a new car when it hits a certain speed it cuts out.
Is my turbo shot?
Car is stock, with the exception of the fuel pump and new gas tank and sender. It ran great till I parked it, then started it up after 5 months and the cut out happened. any thoughts are appreciated.