Engine: 4age big port
Car: ke70
Problem: constantly revs up and down between 1100 and 2000 in a pattern when idling

Here's the lowdown;
Start the car cold and it's a 50/50 it will stall or run rough for 3 sec. Always starts 2nd time. Idles at 2000 like normal cold 4age. Drive the car for a few minutes and then stop at the lights and it will started its rhythmic floating idle.
People think I'm revving at them at the lights!

Now I have disconnect the throttle position sensor and it stops straight away and starts again when reconnected, suggesting its that. I even did a retune with a multimeter which did help the car drive smoother at low speeds.

But when I stick my finger over the auxiliary air hole (the smaller sucking hole on the right in the throttle body) it stops too, so that means it could be the idle speed control valve?

All my knowledge about the problem and the throttle body is from many hours for reading online but many people say different things.

Could a 4age nerd please give me your opinion.
Thanks in advanced
Will