As a follow-up and conclusion to this thread, I spoke with the MSD tech line twice today and was told that I had the magnetic pickup on my Accel distributor wired improperly. I was still using the 4 pin GM HEI module and you are supposed to bypass that completely (the instructions are
very vague on this so it's easy to overlook). After doing so the engine fired right up with the MSD! Also, the reason the unit didn't test properly for spark when shorting the magnetic pickup wires was because (like a big dummy
) I was shorting the magnetic pickup wires that went to the MSD adjustable timing box and not the ones going to the MSD 6AL
.
Now the engine fires right up using the same Optima battery and no charger, thus the battery is also good. The bus voltage measures 12.5V after sitting a few minutes and drops to 11.5-10.8V during cranking, which I was told is normal. The MSD tech guys told me the 6A boxes only require 10V to run correctly.
Finally, I was able to leave the HEI module on my distributor so if the MSD should fail I can swap 4 wires and run the engine fine using only the HEI module and the coil
.
Thanks again for everyone's help!