Hei conversion Intermittent start?

You need a few more tools. A multimeter - free at Harbor Freight w/ coupon and an in-line spark tester - $4 at HF. Insure you get 12 V or higher from coil+ to the mounting screw of the HEI module, with the ignition on. I run a dedicated ground wire from the screw of mine to a good chassis ground. I would never rely on a sheet-metal screw. If you don't measure 12 V, run a jumper wire from a 12 V source (big stud on alternator or starter relay) and another jumper from your iffy mounting screw to a good ground. Don't leave permanently, or you will drain the battery. I don't know if you can damage the HEI module with 12 V on and the engine not running. I think that is OK, unlike the older Mopar module. If none of this makes sense, call in a high school kid who knows basic electrical theory (the difference between current and voltage).