04 Yaris over revving when stood, please help

[Jonty]

Hi everyone,

Im new here so hello to you all! My friend is having a problem with her 04 Yaris when stopping in traffic or at a set of lights. Basically the problem is when changing down to come to a stand still, the car over revs when stood and it seems the only way to stop it is to turn the engine off. When trying to then re start the engine the car wont start up so after being left for a couple of minutes it will then start up and everything works fine. Please could somebody shed some light on this as my friend only wants to take it to a garage as a last resort,

Many thanks,
Jon