1987 Dodge Diplomat won't fire when cold

I don't know how you wired it but I will tell you this, two things, coil requires full 12 volts in start position and less in run poaition(ballast resistor) makes this possible. Without a full 12 volts in start position, the dwell and thus the timing will be different. Also the lean burn provided different advance for starting then running so I would first measure coil voltage in Start position, and if ok, either check another lean burns advance in Start and match it or try turning the distributor and giving it different degrees and see what you get. You know that the system had to use vacuum that was either manifold or ported to work properly also so try changing that. Then get a schematic to go over the differences in the wiring requirements. Sorry I don't have the engine specs for these differences at home with me. I hope I helped in some small way. Good luck and good idea too. You did use the different engine wiring harness correct? The lean burn really caused plenty of early computer changes. It should have used wing nuts for ease of replacement.