Hello,
I have the same problem right now your ignition coil(s) are knackered. It needs to be diagnosed by being put on a machine, this costs between £30 - £40 and then the coils. I had one fail 2 years ago 3weeks later another failed, I was told this was a fault with the Megane's that Renault know about but won't do anything about it, it has something to do with water coming off the bonnet and getting on the coils and shorting them out. I had the other 3 changed at the same time. The same thing is happening again. I am getting rid as soon as it's fixed, don't fancy wasting £400 every 2 years
Dave, January 2007