PCM wiring

Welcome.........I forgot to mention that in systems where there is no longer a ballast, such as MSD or HEI ignition conversions, you need to jumper IG1 to IGN2 and use that one wire to feed the igntion.

IF YOU ARE still using an ignition with a ballast, this becomes a bit more complicated in the case of an EFI because it must be powered during cranking, and the original circuit can cause backfeed problems.