Had the same thing happen to my Nu-Rex, ran good for four years and then began to miss intermittently, then it finally just died. Called Nu-Rex and they said I had caused the failure by do things to the unit that I was not suppose to do. This was not the case, it just died. I was going to buy a replacement control module but I was so annoyed at their attitude I took it off and threw it away. I bought a new setup from a competitor and have not had a minute’s problem. I had 18,000 miles on the Nu-Rex and I have 7,000 miles on the new electronic system. Electronic ignitions have hot sparks but so does a 12 volt system. The last three model A that I have built all have 12 volt points and condenser. No more electronics. I carry a rebuilt distributer with the points already set in case of a failure. I can be running again in 5 Minutes. I am not going to use any more electronic ignitions.