Need help diagnoseing 94 runner auto problems

94 Runner with a A430H

When I put it in gear I have to rev it to about 3000rpm for 10 seconds before the tranny will engage. Doesn't matter if it's reverse or drive, same thing. Once it's moving it does ok. right around 40mph it seems like it doesn't know what gear it should be in and keeps up and down shifting. kick down works, im baffled.

Can I put a code reader on it?

any ideas?

TIA,
Steve

first of all, I would check for leaks. if none found, check fluid levels, smell ( if burnt smell), check for color, oxidation on dipstick. if everything ok, check cable adjustments and vacuum lines if applicable. for loose or broken. might be TV cable or governor sticking. if you never changed the fluid, now might be a great time to change that and the filter, an maybe even an overhaul of clutches and bands.... first way to tell is check your fluid .... good luck.