The engine harness on a hotwire Plus 8 is straight from Land Rover, engine electrics, including ignition is as per Land Rover.
At one point I suspected an issue with a coil and spent some time testing coils I had used from Bosch, Intermotor, and a generic coil from CCL. In general the inductance of primary and secondary was the same, coil ratio the same. The resistance of primary and secondary varies with temperature, the three coils demonstrated a similar change in resistance from room temperature up to 100 degrees C. I was trying to see if I could make the coils fail, but they resisted my attempt.
Finally I found the issue (occasional confused.com running, and the odd failure to start) was due to the pick up coil in the distributor. To measure the gap between coil and toothed rotor I used a piece of thick card, this had the inadvertent effect of also cleaning the surfaces, and from that day the issue was resolved, although I did replace the pickup as a precaution.
The other ignition problem I have had on the Plus 8 is the fairly common problem with rotor arms, I did buy a stock of the 'good' rotor arms.
I am currently running a Bosch 0 221 122 392 coil
