Could be a number of renault issues..
1: Defective Spark Plug/plugs.. Solution: tech note issued by Renault UK, It goes by the date code stamped on the plugs..
2: Faulty Upper Engine loom and/or Map sensor.. Solution: tech note issued by Renault UK, Possibly having to replace either Map sensor and/or upper engine loom
3: Injection Computer Map.. Solution: tech note issued by Renault UK, Reprogram Injection Computer to cure lumpy idle/stalling etc
4: Defective Injector.. Solution: No tech note issued but I have had to change individual faulty injectors on half a dozen of these 1.2 engines.. Takes a little while to diagnose due to the way the inlet manifold is routed and the inability to remove the injector plug/harness.
5: Damaged Upper engine loom.. Where the anti tamper cover on the loom connector at the rear of the engine moves and chaffs the cable. So causing poor running stalling etc.. Solution is to renew the loom and apply a rubber sleave to the cover to stop it happening again..