Baro solenoid should on passenger strut tower. I had an 87 turbo II years ago. Every time mine would chuck one of the brittle plastic vac. lines it would overboost. When it goes into overboost it pulls real hard then shuts down real hard. Just about throw you through the windshield. I was 19 when I had that car. I would like to have another one. What color are the plugs? It could very well be dying fuel pump. My SRT-4 sorta the did the same thing a few years ago on my way to the Nats. It ran great until you tried to get into boost. I drove it easy all weekend, then changed out the pump once home, and all was good.