I have a 393 windsor which I recently built, and I decided to get new plug wires to match the motor (old ones orange, new ones blue). I was running 7.5mm Autolites, and I bought Moroso Spiral core 9mm wires. My car won't run with the Morosos. I have a Petronix coil running off the factory ignition connection (resisted), a Pertronix Ignitor I and a stock cap with Champion plugs. The car runs great with the Autolites. The resistence on the Morosos is less than the Autolites as measured with an ohmeter. When I replace one wire at a time it will run without a miss that I can notice, but when I tried to start it after replacing 4 wires it would not start. The Moroso guys are baffled as to why it wont run, as am I. I will try and run 12v to the coil this weekend, but I have never had a car refuse to run just with a plug wire change. Thoughts?
I wonder if there is electrical noise (emi/rf) from the new wires that is messing up the Ignitor? I have Ford Racing 9mm spiral wires and an Ignitor, they seem to work ok together. If it is an electrical noise problem, most of the noise will come from the center lead that goes to the coil. Try putting on the new wires to the plugs and use your old coil wire just to see if it makes a difference.
