Senior Tech Team
Join Date: Apr 2012
Location: Yerington, Nevada
Re: HEI pro billet install problem
There are two distinct problems that HEI's have brand new for some.
One is a new defective coil, happens a lot more than people think.
The second is that possibility that the electrical connectors crimped to the magnetic pickup wires into the module connector were compromised when the pickup was built. It is possible the crimp tool has cut a number, of, or all of the wire strands on one of the pickup wires, stopping the spark.
You mentioned that the distributor fired right up with the other cap and coil. Take a close look at the coil itself under the cover on the cap. There are two grounding areas those caps use that other caps don't. Both grounds need to ground to the coil yoke, the metal band around the coil. One screw holds the ring terminal out of the coil, to the coil mounting yoke, the other screw holds the grounding buss bar to the yoke, is the center terminal in the three wire connector at the side of the cap. The grounding bar fits under the coil yoke, between yoke and cap.
Once assembled, do a continuity test frm the ring terminal screw on the yoke, to the center terminal of the 3 wire connector, should be good, clean continuity. If not, pull the coil out of the cap, confirm the connections from it and the yoke are clean and working.
To test the coil, it should be run on an off vehicle electrical tester, but an in field test can be made tor continuity between the ring terminal and the TACH wire on the coil. Should have correct resistance. This is not the right way to test the coil, but if the coil is new defective, it just might show it right off.
My thought is that the MSD coil is new defective, might be wrong, but have seen more of them DOA than I cared to see over the decades.