You are problem with Ford Focus

The vehicle when part stops if you do not keep them accelerated while it is cold, but after it heats there is no problem, the tests of the water temperature sensor is carried out (this model only brings a water sensor that serves for the fan, for the needle, and of temperature sensor) and the IAC but everything went normal

And in high the escape is heard even or does it have interruptions?

Check tested valve, do you feel your brake pedal hard?

In high no problem only in low and that the vehicle and short injection are paired and does not fail, the brake pedal is normal, the IAC also cleaned it ...

Mmmmm is weird how did you check the temperature sensor?