msd 6a fault???

I had problem with msd 6al I did some of the same things you did tracking fuel problems I even had their pro billet distributor and msd coil. I canned the whole msd system went back to mopar setup, 2 years later no more ignition problems. Msd will repair the unit but for a price plus shipping. Google MSD problems you can see for yourself these things are far from bullet proof.