That happened to me yesterday down in the states. BAM! BOOM! Lots of brown smoke! Dead on the side of the road. I look and the coil is putting out maybe 1.5 volts, a weak pink spark. I was given a ride to a car parts store and they had a universal 6 volt coil that I installed and the car was fine after running for a few minutes. It sounds like I blew out an exhaust gasket also. I’m thinking that a lot of unburnt petrol was igniting intermittently causing the noise. My question is, while the car ran OK, can I expect any engine damage such as a blown head gasket? Damaged pistons? The noise was loud like gunfire. Not fun. Any advice?