I've been searching throughout the electrical and fuel systems on my small block trying to figure out why it won't idle with out rattling (sounds like occasional dieseling). Well I finally pulled out the multimeter and I only have 5 volts across the coil and ballast resistor. I figured I would have 12.8V minus the drop across the ballast, so maybe 10 or so volts.

The car is a 74 Duster with dual field alternator, electronic voltage regulator, MP Orange box, single ballast and a MP electronic distributor and a Blaster 2 coil. Prior to my new findings above, I swapped coils, ballast, cap, wires, ECU and regapped and check resistance across the pickup coil. None of these changes made any difference to how it ran.

Does anyone have any idea why the voltage is so low at the coil? I visually checked the wiring, but everything looks pretty good as the engine harness was replaced 8-10 years ago.