I would try a little troubleshooting before you start pulling TDCs, etc.. If its turning over with the starter then one of two things is missing. A spark, and/or fuel. For a start, I'd pull a plug and see if its wet (suggests fuel is reaching the pot), then, with the plug resting on the block, turn it over to see if there is a spark. You may need to do this twice, as many renaults have multiple
. My wife's Megane Coupe had this problem - both
had failed. Started with irregular starts, then one day completely packed in. £250 later problem sorted. Also pull the fuel line, and make sure fuel is reaching the fuel gallery for the fuel injection. When you turn on the ignition but before engaging the starter listen out for the fuel pump. It should operate momentarily while it pressures the fuel line.
If you're getting a spark and the fuel is there, then I 'd have thought about the
, etc. Unfortunately, there are more sensors on these cars than you can shake a stick at, and a fault with pretty much any one of them can bring the machine to a halt. Oh for the days of a simple normally aspirated engine, with a set of points and
Just my thoughts for what they are worth. Good luck.