My renault N reg. renault laguna keeps cutting off when the engine is hot.???

WHEN THE ENGINE IS HOT, THE POWER CUTS OFF, THEN THE ENGINE STOPS AND IT TAKES AGES TO START IT AGAIN. BEEN CAUGHT AT A ROUNDABOUT, DANGEROUS WHEN IT DOESNTACCELERATE WHEN YOU PUSHING THE PEDAL!!!!! CHANGED THE COIL, HT LEADS, FUEL FILTER, DISTRIBUTOR CAP, SPARK PLUGS FINE. ANYONE CAN HELP ?????