Sorry, it's me back again. Have tried new TDC sensor with old connector (shaved off two plastic lugs as mentioned in RenaultForum instead of rewiring new plug). Engine starts in same way (now easily but very rough) with old or new sensor so I now suspect coils. Coils last changed 13,400 miles ago and was told by Renault Main Dealer that the old batch had been superceded by new coils from new manufacturer. Looking at threads on "coils" I suspect my "new" coils were not from a new manufacturer (they are grey Sagem's). They have lasted almost exactly half the mileage of the first set! Any suggestions as to how to approach the Dealer who so far has done all my servicing .... this appears to be a "known fault" which still has not been resolved ... or was I fobbed off with the same type of old faulty coils?