Renault Megane '98, 1.6 RT Sport, Petrol. Over the last week this problem has started, and slightly progressed. The car kangaroos when trying to hold (or accelerate slowly / normally) the revs at around 2,000 - 2,250. It feels worse the lower the gear, and hardly noticable in 4th or 5th (doesn't kangaroo, just stutters slightly). It makes driving in traffic very difficult. I suppose it's either an electric or fuel proble. I seem to get some smoke out the back (this could be due to high revving, as I can get round the problem by riding the clutch) and sometimes a smell of fuel (maybe where it's not getting burnt. If some one could advise where to start. I'm thinking of changing leads and plugs as a matter of course. Please advise.
If the car has been serviced recently I would only change the leads and fuel filter. If not, I'd service the whole thing.
Aslo check the distributor cap and rotor arm for wear and condensation.
Failing that, the next place I'd start looking is the fuel supply.