Toyota Repair: Engine dies immediately during restart when hot only., valve cover gasket, camry v6

Question
I am a 'shadetree DIY' and have a 93 Camry V6 LE with 127,000 kilometers. I am 2nd owner and upon my purchase 3 years ago, I noticed the PO neglect for regular service. I have since replaced plugs, rotor, cap, wires, air filter, tranny fluid drained twice, air filter, PCV valve (the original was blocked with oily carbon type gunk as was the small hose from PCV leading to the intake!!), front valve cover gasket, temp. thermostat + coolant, cleaned throttle body (as best as I could without poking to far or hard with t/brush in the TB area) so far on the engine side, all with dealer parts. Oil changes are regular and once in a while, I use injector clean (sometimes the small powerful clean from the dealer). Car perform wonderful with no major problem and mileage is good. An occasional problem I have is when the car has been driven a bit and the engine hot, the car will die immediately upon restart. It will start up right away but die again unless I press the gas pedal. Sometimes it will stutter, and get to idle or die again. Once on idle, it is fine. Problem not duplicated when the engine is cold. This problem does not appear every time also. The only thing I have not changed is the gas filter. I recently cleaned the TB again noticing a good layer of sooty gum. What is the cure for my stalling problem and I am also curious where all this gummy deposits in the TB area and intake is coming from? I have read the deposits are from gas evaporation etc. I thought this intake area was for 'air' only. Do I need to clean the IAC valve, if so please advise where and how without much removal of parts in this area. Any help offered is appreciated..Hitesh

Answer
Hello Hitesh,welcome to my expert page.
Yes you do need to clean the IAC valve, it's located on the bottom of the throttle body, everytime the throttle body is cleaned all that gunk goes into the valve, heat from the engine turns it into carbon-like deposits and makes the valve stick.
The throttle body needs to be removed so you can access the IAC valve, then clean it with a spray throttle body cleaner.