Your Right, I don't want people to think they fail on a regular basic, but based on the symptoms, This could be happening. The 20 year old ignition coil will build up a high resistance, start to weaken and can very easy start to intermit because of the electrical make up of wires, heat and solder joints. Hot and cold. If there is 6000 cars on the road and one /month fails, is that low or high. I would say low. I replace the ignition coil at every 50,000 miles on any car, due to potential problems. Yes, you may get some that could be a lifetime, but I just don't want to worry about it since it's a low dollar item and it will help the car run better. That's me. The impulse coil is the same way, I have one that failed in 11004, You can check resistance cold and there right on the money, but put a hair dryer over them for about 3 to 5 minuets and they open up. Again, You won't fine these in stock normally anywhere, so for $29.00 or so, if I have access to the distributor, I would replace it and then not worry any more. As in any circuit, not just the De Lorean, Where wires,solder joints,relays,contacts are concerned, there is a reason to try to do preventive maintenance. Something a simple as pulling the fuses in and out a couple of times in the socket, You may find a weak contact and over time will heat up and cause the fuse or fuse block to melt. I could rattle about more things on the car, electrical to check. But above would be some of the more common. John Hervey www.specialTauto.com I anyone wants me elaborate more on how the coils can fail. Please email me direct.