Rich, use a vacuum pump, one of the hand held deals, to activate the vacuum advance at idle, see if you get the problem.
If you do, use a pair of needle nose pliers to pull on the little wires where they come out of the pick-up coil in the HEI. Sometimes these get old and break inside the insulation. Pull on the wires gently, if one of them is more like a rubber band than a copper wire you've found the problem.
If you do, use a pair of needle nose pliers to pull on the little wires where they come out of the pick-up coil in the HEI. Sometimes these get old and break inside the insulation. Pull on the wires gently, if one of them is more like a rubber band than a copper wire you've found the problem.
