Power Steering or Rack?
 

1987 Supra 7mGE 205k
PS Reservoir Full- Has PS Fluid in it, NOT DEXRON II/III
No Leaks
Belt is tight
Fluid burped

My power steering only reduces the effort to turn the wheels about 15%, Would you guys say that the power steering pump or the rack is bad. It does not work consistently but it is also not relative to wheel angle, just some turns it will work and others it will not, but it never works more than about 15%...

Ideas?

Would it having the wrong fluid in it be enough to make it not work?

Yes. It is

Drain refill with proper fluid. And hope seals did not get damaged. The ps manufacture said to use atf for a reason. All fluids have different detergents (if any), lubrication capabilitys, compressability at diff. Temp ranges. And can even vary from the base oil such a mineral based or petrol, which will determine what material the seals are made out of. So yes the type of fluid they say to use should ONLY BE USED!

Mine was doin the similar thing with the correct fluid. I added some BARS powersteering fluid additive and it took care of it.