Have had no problems for the past 80K miles but suddenly when it runs for some minutes specially when pressing the brake peddal the engines shuts off and wont turn back on unlessI let it cool down for about 45 minutes or so, cooling systems is good, new timing belt and serviced not too long ago, is there any chance the coils are failling or some kind of module system like in the old fords??

 

Probably a sensor, most likely the Crankshaft Position Sensor, from what I've heard. Could also be a bad ignition switch (a problem I had with an Escort). But my local Hyundai mechanic said when an older Elantra randomly cuts off or won't start, the Cranshaft Position Sensor is where he starts.