Chk your fuel pump fuses- test them. Voltage could be off. My pumps were only buzzing when this happened and chk your coil- might not go with your msd. Go with an msd epoxy.
Let me add this also---I INMOP- these MSD6AL-ARE JUNK---For it to fail in less than 6yrs-(purchased new 2008) made USA-. Less than 2000 miles a year on the car... And a lousy 30-day warranty. Spoke with tech- regarding why so many parts had to be replace,,,Not much of an answer. The tech expressed the Box-needs air flow (Hugh
--even though I told him I had in the cockpit.. NOT- much confidence in their product. A lot of racing blogs express the same opinions with little to no alternative for a 2nd choice.