Ok, weird problem here. I have a 93 es300 automatic. I noticed the other day that when I floor the accelerator and accelerate hard that the rpms will climb as they should and the car picks up speed like it should until it gets up to about 5500 rpm or so and then instead of shifting to the next gear it slips out of gear and the rpms really shoot up like I am in neutral or something.

If I do the same scenario but ease off just a bit it will shift like it should. I have new fluid in the tranny from drain and fills, new tranny filter, the fluid is topped off. I have no other issue any other time with the shifting. Could this be a tps sensor issue or some other sensor not telling the main computer that it should shift at some point with the throttle wide open?

 

Try adjusting the throttle valve cable that goes to the transmission, here is an article explaining it:

https://www.clublexus.com/forums/es3...-shifting.html