New Subscriber(s): Ed Hesse Email Address is: prntbear@xxxxxxxxxxxxx Member Location: Philadelphia Car(s) owned: Self-Introduction: Recently acquired 68 Coupe has a new tune up and I noticed an crankcase overfill which I have corrected. Long list of "to-do's" so I'm starting with the first and biggest issue: I have a serious engine problem. The engine is running terribly rough with black smoke coming from the exhaust. Plugs 1,3,5,7 look normal but plugs 2,4,6,8 have heavy carbon deposit. Have replaced fuel filter, tightened carb and checked for vacuum leaks.There seems to be a moment of smooth running when the engine is first started, and then it gradually gets rougher until it will no longer idle properly and stalls. Let it sit for a while, hours, and then the same thing. Also ran smooth when it was running out of gas. It is using up gas faster than I can replace it. As it is a sorry sight, I have avoided putting it on the road until I have the smoke cleared up, no pun intended. It looks bad to me. Any suggestions? EdH '68 Crown Coupe