Iīve got great news!!!
Problem found and solved.
I must say I didnīt change the thermostat yet...
I knew the problem I had, was not related with it so I did not want to change operating parameters (like temp), before I found the cause of the malfuntion.
And also because the problem showed more when the car was hot, so if it was hotter I had a car that "didnīt" have idle speed, at 90š I had to touch the throttle to keep the engine running...
The problem was random, one day I had the idle/stall, the other day also, but the day after it was almost all right, but was never perfect.
So today I bought carb cleaner spray, and remove all plastic/rubber, MAF to inspect and clean.
The two rubber tubes were perfect, the bigger one looks almost new. I cleaned bought. The one after the MAF (bigger) was a bit more dirty inside with some traces of oil, but not much. The MAF was cleaned, but I cleaned again. The butterfly was very clean with no traces of deposits, a very clean aluminium, but I sprayed some carb cleaner just in case...
I also cleanned all electric connections I could see.
After that I put everything back together started the car and... everything like it was.
After that I did a reset on the throttle potenciometer and to the ECU... but nothing different.
I start to study all the intake and the sensors, injection and tried to check everything so at one point I was checking the butterfly/throttle potenciometer/idle actuator
and... it was loose!!!
The f#$%ing idle electric actuator was LOOSE!!!
It has two screws, one up and another down, and the down one was very loose and the electric motor/actuator could move and also ar could pass...
I got a short screw driver (small space because its very near the back of the engine bay) I tighten the screws and... the car is PERFECT.
So guys... if you have idle problems on the theese engines, first thing to check is if the idle electric engine/actuator is correct screwed
to the throttle body.
Thanks again to all that tried to help.