Earlier Toyotas (4Runners) would not shift into high gear until the engine was warmed up to operating temperature. Sounds like you are pushing it too fast/hard -- you must be doing 60 or 70 MPH? You should drive gently til the engine is warmed up to avoid serious engine wear.
During the first run up through the gears after setting all night or all
> day, I am getting an overrev between the last two gears. It only does it
> once or twice until the running temp comes up. I've varied the throttle
> pressure and it doesn't seem to affect it either way. The truck has about
> 2500 miles on it. Anyone else seen this?
>