Intermitent backfiring

[ERA 778]

Something doesn't sound right or I am missing something. For the MSD 6 series of ignitions, there should be two wires from the box running to the coil. There should not be a ground wire at the coil. Both the orange(+) and black(-) wires should run from the coil back to the MSD box. I suppose that if the engine ran before with the coil wire grounded, then an intermittent connection could explain your problem, but I just don't know if an MSD system can run if wired the way you described.

Also, if the problem actually was with the coil, relocating a bad coil should not fix the problem.

[BAsque1]

Originally Posted by ERA 778

Something doesn't sound right or I am missing something. For the MSD 6 series of ignitions, there should be two wires from the box running to the coil. There should not be a ground wire at the coil. Both the orange(+) and black(-) wires should run from the coil back to the MSD box. I suppose that if the engine ran before with the coil wire grounded, then an intermittent connection could explain your problem, but I just don't know if an MSD system can run if wired the way you described.

Also, if the problem actually was with the coil, relocating a bad coil should not fix the problem.

The two wires are indeed connected to the coil but the ground wire that I am talking about comes from the loom from the box and it was a ground wire as per the directions. This MSD system has been in my car for over 2 years now without a hitch. I just relocated the coil in the vertical position just for peace of mind.
I will report back after my next longer test drive, but it seems that the backfiring is gone.