l have a renault megane scenic 1.6estate 5 seater p reg which is defficult to start in the morning.l have to rev it for it to start.l bought a new battery but nithing changed.When it starts l can drive it but on reaching traffic lights it turn off when l break.When l move at leat4 to 5 miles and the engine is warm it can start on its on without reving.During driving the car could sometimes starts hesitating and losing power even if l acceletate.it can some time move at speed of 40/50 miles without accelerating.If l try to changegears that is if l press clutch pedal down it produces a very sharp loud reving sound(pink sound).If l rev it hard then it could turn off or the pink sound cound seize but on continue driving the hesitation would come back .it seems as though there is something pushing the car back whilst l accelerate forward.Please can you tell me what could be wrong with this car.

Try poring some injector cleaner in the tank