OK. 93 civic has been out of service for way too long. Problem began over last summer with no starts on hot afternoons after cooking in the parking lot all day. New main relay solved this. Next problem came when the car randomly decided to stall, always within 20 minutes of starting, but not stalling on every outing. Always restarted like magic after waiting, draging home, or breaking battery contact. Never had any error codes with service connector jumped. Very frustrating. Finally we were lucky enough to have the thing stall and not restart. Pulled ICM and had tested at auto zone. Very pleased to see it fail their tests. Installed the new igniter, turned the key, and we ran for about 15 seconds before check engine light came on and car died. After looking over my amateur repair I discovered the spark plug extension tubes were merely resting in the holes but not seated fully on the plug ends. Popped them back down and tried to run again, but same result. Thought maybe I fried the new igniter by trying to jump gaps with spark, so pulled ICM and had tested again, and passed.
the coil is not open, and resistance checks out on all three sensors in the distributor. When it does run, I tried disconnecting the map sensor and we got a quick stall and code 3 flashing over and over. Now the check engine light just stays solid almost all the time, and the car won't start. Traced the 5 volt supply wire from the ECM to the map sensor and it only gets about 1.5 volts with the key ON. Also that thermostat bundle of grounds looks good and tight and clean. Also erratic movement noted at shift lock solenoid. Bad ECM?

Failed the K-Test; therefore, a bad ECM. You may enjoy reading sections A and B below:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-46563.html

Just wanted to post the end of this story. I put a new ECM in the car today and she started right up. Driving tests confirm this was the fix we needed. All the advice on this site from txgreasemonkey was a huge help. I do suspect that the auto zone test rig gave a false negative on the ICM being bad, but that's fine because it was likely just a matter of time before it went out anyway.

curbsidemechanic, I'm glad the material helped you. Could I get you to update the K-Test Poll below:

https://www.askmehelpdesk.com/cars-trucks/k-test-poll-51138.html?highlight=k-test+poll

Thanks.