Sounds like the high pressure switch on the power streering or the intake gaskets have begun leaking. Verify all other electical connections (especially to the MAS) first then unplug the wire that goes to the PS switch to eliminate that as the cause (vmag has a better description of it).

To test for intake leaks, get a can of starter spray and spray around the edges of the intake manifold - if it speeds up, you have a leak and the gasket(s) will need to be replaced - good time to upgrade to a supercharger while you have the intake off!