Having spent months farting around with my recently bought series 2 aiming for all round acceptable running I concluded the AED and distributor were main culprits of all issues providing the mechanics and electrics of your engine are in good order. As such I resigned myself to accepting the AED is near impossible to repair, and the distributor can play havoc if the bushes are worn and it's expensive to re-build. I've spent lot's of time and money on used (and useless) AED, new points, condenser, coil, distributor cap HT leads, plugs etc. and manual choke conversion for the AED, the latter of which still relies on primary funtions of the AED carb being in good order and plays up otherwise. Having fitted a brand new AED and 123 Tune + bluetooth distributor I cannot tell you how much better the car runs and most importantly I feel I can drive the car with high confidence and that it won't let me down. Not a cheap route but for the sake of your sanity, time, around 1100 GBP and less than a days do it yourself work i can tell you it's well worth it--runs like a dream !!