Originally Posted by
DS3R
could be;
Idle control valve or a related breather (carb cleaner sprayed through would show if anything a problem, unlikely though if it is *always* heat related),
fuel relay or fuel pressure regulator, but may give problems on starting (ie it won't),
Think that engine has coils on to the plugs? When heated they can shut down as they break up over time anyway, thwt might show as occasionally misfiring when starting from cold at first, then when overheating the sensors will cut the fuel.
Crank position sensors on all french petrol cars don't last.
If a coil has gone you'll be pouring unburnt fuel on to the cat (think they had them from 98), which will kill it come test time (if they have them in France!?!) Ad a coil pack is about £15 (x4 if needed), a cat is £200. code reader should tell you if it's a sensor or the ECU has shut the engine down cos of one or more of the coils, because it is trying to save you cat for you.