Look closely at the rotor....it might have an arc-thru so that the energy path is directly to the distribuotr shaft. If you see a carbon dot on the underside of the rotor, it might be such. Try a quality rotor...a Delco or a Blue Point.....most others are crap, especially the junk brands like Accel and Mallory. When you remove a rotor that has an arc-thru and put it back, the engine usually fires but doesnt run long before the leak is re-established.