Were you given the fault codes ??
I would only recommend genuine Renault parts on an engine which is so sensitive .
Trying to diagnose is hard without looking at it . If compression is good which it sound like it is if it goes like stink I would start with the
sensor which is cheap give it a clean ?A local garage will do this .
Have you checked and cleaned your idle valve ??
As this can cause your problem .
If you have had it into renault what have they done and how much have they charged .??
If you take it into a Reg vardy renault dealer for something minor they do a free health check on the vehicle .
They then tell you any faults and the cure and they also give you a quote for the work (well they did at the one in Harrogate ) I was very impressed .
As my air con had stopped working and I couldnt figure it out but within 10 minutes they had told me the problem which I then rectified myself .
But a word of warning all dealers are different .
Start with the sensors I have mentioned and I would have a word with Mushroom a forum member who I believe had your problem and this was to do with the air intake .
As for your esp system what is it doing ??