It is difficult to diagnose, everything on modern motors goes through an ECU, Renaults in particular are one motor I wouldn't touch with a barge pole, have you seen the number of problems on this forum regarding misfires,window regulators,card readers,immobilisers, I would get it onto a good code reader/computer, on there will be activations you can go through,ie shutting off fuel injectors in turn to see what cylinder is giving you problems,some can also measure low compressions on each cylinder,also it may pick up fault codes other code readers may miss, the days of pulling plug leads and adjusting points are well and truly over. Good luck.
cdc, February 2016
