idle is rough, unsteady and revs bounce about 700-1000 RPM even when engine is warm.

cause 1. highpressure pump has failed, the internals have probably gone into fragments and are now blocking the injectors.

cause 2.injector failure a common prblem on 1.9 2.0 DCI renault engines, depending on what type of fuel pump you have a fly by wire or a mechanical high pressure pump, the injectors go down either as a single or as a pair 1 and 3 or 2 and 4 injectors, injectors are coded to the cars ecu and cannot be changed without the new injectors being programed.

cause 3. the cheapest, idle speed control, egr valve blocked, catalytic converter failed, lambda sensor failed, thorttle positione sensor failed.