What kind of shape is the top of the intake? Did you use a new gasket between the throttle plate and the manifold? If the throttle plate binds after you sock it down, then something is distorting that part. Make sure there are no pieces of trash between the carb base and the manifold. You still didn't say where the blue RTV came from. That could be a give away as to where your problem might be. Also, if the engine has done any backfiring, the throttle shaft might be slightly bent.
1987 BMW 325