Practically Classics Forum

I have a 1972 Opel Kadett 1.2 and it has started running rough,it will tick over fine,but anything more and it starts coughing a bit,sort of like its running on 3 cylinders,i did start tinkering with the carb air mixture screw(which i probably shouldnt of i sure)and i dont think it is anything to do with this,so far i have replaced the spark plugs and HT leads and the problem persists,car was fitted with electronic ignition a long time ago so im not sure if the distributor cap and rotor arm are redundant but i have visualy checked these anyway and they seem ok,can anyone advise me on what to do next?
Many Thanks

Have you been feeding unleaded fuel to it? If so, have a compression check done.

No i always put in the lead additive,i think ive cured the problem,had another look today and was thinking about replacing the coil,when i started taking the wires of the coil i noticed one didnt seem secure enough in the crimp connecter,so i remade the end and it is now running fine,so problem seems to be cured....thankyou for the reply

Excellent, a free fix, they're the best type.