1990 Miata Automatic Trans Vacuum Line
 

It appears that the vacuum line from the rear of the intake manifold has come loose. Where does it connect? Problem is no power on acceleration. Replaced all other vacuum lines (problem not fixed), when I noticed this hose just hanging there, not connecting to anything.

Makes me wonder if that is the vac line that should be hooked up to the MAP sensor, that would make the engine run poorly and not make power. Can you take a picture so we know where and what were looking at? Welcome to the forums!

If you can't figure out where it plugs to try plugging it up with a bolt. But it should go somewhere.