1994 honda civic (D16Z6 Engine) Automatic transmission problems
 

It's a little odd what it does, but anyways. It's like it just refuses to shift after the transmission gets around operating temperature (after about 20-25 minutes of driving), it gears down and sticks in 3rd, and then sometimes when it gets worse, it'll downshift to 2nd and won't go any higher. The engine revs continuously and does not shift. I've replaced the speed sensor (speedometer wasn't working, still isn't.) seeing if that'd help anything, but it didn't. Are Honda's just that picky as to what fluid you use in them (I've been using Castrol Import-Vehicle ATF, the fluid in it leaks a bit and I have to keep an eye on it). What could the problem here? Any help is appreciated.