Turbo question for my Impulse RS

Car is a '91 Impulse RS it has been sitting for about 6 years. I've replaced fuel pump and filter. I've redone the grounds. New coil packs, checked timing, resoldered CAS. Starts nice and revs smoothly to redline when parked. Under load it hits fuel cut. Feels to me like overboost protection. MAP tests good and I replaced vacuum lines to MAP. The oil return line is leaking. I know the wastegate is actuating but I'm wondering if it is sticking. Fuel cut isn't at a consistent rpm or throttle level but definitely feels related to boost building. I think carbon buildup and leaking oil may be the culprit but I wanted your opinion before I tore the turbo apart.

The waste gate could be sticking or a issue with vacuum line/ control valve. I would also take a good look at the TPS voltage and related sensors that also use the common voltage and ground.

Paul B

Hook up a cheap boost gauge and verify it is making the amount it should. Also, perform a boost leak test and make sure the system is holding pressure correctly

Boost gauge is a good idea to verify if it's hitting overboost. Trying to think of what sensors would trigger a hard fuel cut. I don't think tps or O2 would do it maybe something with the rev limiter. No gauges at the moment so I'm somewhat flying blind.

ECU seeing more air than it expects for a given load is enough to trigger fuel cut.