I would guess time to replace your pump or rebuild it. I just blew out my second pump after i did my 3.4 swap. Up until they have gone bad for me the steering has been fine.
Both times they have gone out (well on the ride home) i notice if i rev the motor up while steering it will somewhat assist the steering, but very poorly. If i try to coast through a slower turn i feel like im gonna break the steering wheel. Anyways, time to tear my steeeing pump off and replace it. Again.
Good luck.
