Toyota Repair: 2001 HIghlander - fails to restart or idle properly without giving some gas w/ accelerator, highlander 4, solenoid valve

Question
Hello, Ted-
I have a 2001 Highlander, 4 cyl, 192,000 miles.
About a year ago, I had stopped for 5 minutes and shut off the engine, after driving for over an hour. The Highlander failed to restart without me giving some gas. When I let me foot off of the accelerator, it would stall. After nursing the car home by riding the accelerator a little when I cam to a stop, this went away.

About a month ago, this symptom reappeared, then went away again.

The past weekend, it seems to have reappeared and is almost a permanent feature now. Occasionally, I can re-start a warm car, and it won't stall, but more often than not, it stalls.

Now, the strange part, is that after starting (again, with my foot on the pedal to give some fuel), if I punch it while in Park or Neutral, to about 5500 RPM, then when the RPMs drop down, the car will idle properly.

This punching the RPMs seemed odd. I would normally suspect the air idle solenoid/valve needs cleaning - it would be consistent with a car with this kind of mileage. Of course, living in upstate NY, when I tried to remove it from the throttle body, the screws were rust-welded and I started stripping the Phillips heads. I don't mind drilling the screws out and re-chasing the threads, but I wanted confirmation that this is where I should be looking before I did the drill-and-tap.

Any and all advice would be gratefully received. Thanks

Greg

Answer
Hello, does the check engine light turn on while driving?
This engine doesn't use the IAC valve like earlier models, the idle is controlled by the computer with a idle control motor, if the check engine light is not staying on try cleaning the inside of the throttle body, use a brush and a can of decarbon spray and clean all the dposits out, block the throttle plate open, disconnect the battery for about one minute and see if that helped/