I drive a 93 4runner and the transmission has trouble shifting into overdrive. The 4runner will warm up and the transmission will not shift into overdrive. Then once every blue moon, the car will find overdrive. I make the same drive every day (the 4runner warms up), might shift into overdrive 1 out f 10 times. I don’t know where the problem is.

 

I have a similar problem except that it works better when it warms up and does horribly when cold.

 

I had that problem. I took it to the transmission place and they had to replace the sensors and selenoids in the transmission. Cost me about $500. You might have diagnosed the prob now since this thread is old.