Hey Scotty, I got a 2007 Toyota voxy with 240,000 miles, on a cold start the fast rev would take a second to surge could it be a fast idle thermo valve or idle air control valve that is bad?
Sounds like your IACvalve is sticking.
Grab some carb/throttle body cleaner.
Take it off of the throttle body.
You'll see a little vane in there. (in the guy's right hand) It's in the dark cavity on the upper left..
It's probably sticking.
So get a couple lengths of wire and connect them to the + and - terminals on your battery.
There's 3 pins on the electrical connector of the IAC valve.
Attach the positive wire to the center connection of the valve.
When you touch the negative wire to one of the other 2 connectors it should fully open.
Touch the negative wire to the 3rd connector it should fully close.
If it's hanging up try cleaning it.
If that doesn't free it up, replace it.
Thanks Jack I will see what I can do