On the 85 turbo

Your description sounds like the older K-Jet system. This system uses fuel pressure to put "back-force" against the arm the plate is attached to. This prevents the plate from opening up all the way and dumping fuel into the engine.

It sounds as though it has to much pressure. I would make sure the fuel return line is not blocked. Perhaps the fuel pressure valve in the regulator is stuck. If I remember correctly it is mounted in the side of the fuel dist. Looks like a bolt head. You might try removing this and anything that comes out with it and clean. You might also get a bently manual or some other reference, to verify all the components are in correctly.

I know this is not very discriptive, but I hope it helps.

Joe