Toyota Repair: RAV4 Cold start problem, air control valve, coolant level

Question
I have a JDM 1997 RAV4 with 3S-GE engine automatic with odometer-112,000km. When I start the vehicle after not using for few days, engine stalls if I don't press the accelerator. As long as I use the vehicle frequently it does not happen. I noticed that when the outside temperature is cold the period that I have to not use the car for this symptom to appear is shortened. It is difficult to diagnose at a mechanic since the car has to be not used for few days for the this to occur.
I had this problem for about 6 months.
I don't know if these are connected. But recently the vehicle over heated couple of times about 1 month apart and both times when I opened the engine the radiator fans were not working. First time I checked coolant level was low I thought it might be the cause and added coolant to top up. To check if the fans are working I kept the engine idling for about 20 minutes and then the fans did run briefly.
Check engine light does not illuminate.
Will there be a diagnostic error code without check engine light coming up?
What might be causing these issues?
Thanks.

Answer
The stalling condition is usually caused by a sticking idle air control valve, the throttle body has to be removed to get to the valve, the valve can be removed and cleaned but if corroded or sticking severely then it should be replaced.At the same time the throttle body should be cleaned on the inside.