4 pin ECU doesn't work. Old 5 pin does.

Sorry Red, was on vacation and missed this. Just got the NOS 5 pin I'm going to try next. I'm right in the middle of a new harness install so it might be a couple days before I do.

If it doesn't work after this, that could compound things!

Have you tried grounding directly to battery?? I had one that had a clean bolted ground to inner fender. Wouldn't run. Lifted the ecu up and it started running, while sparking and thus grounding to firewall. The fender wasn't grounded.