got a set of 071's in a stg 1 cossie. it recently started running on 3, so pulling off the leads one by one i could diagnose that no.1 was the culprit.
took the plug out and had a look, but not much to see. took all plugs out and cleaned them and checked and set gaps at 0.6mm (std coil), but put the plug from no.1 back into no.4. then it runs on 3 still, but this time no.4 is the culprit (so can't be the leads or HT system or anything else apart from plug)
now the strange thing (well to me anyway). when pulling the lead off the plug and putting it back on, i noticed that if the lead is properly plugged on it misfires, but if the lead is just rested on top of the plug, it fires properly
any ideas? obviously i'm going to replace the plug anyway, but i'd like to know why this happens