My '93 Civic will turn over but when we check the spark plugs the spark was really really weak. We then went on a two day long project of replacing every thing. The distributer car, rotor, ICM, coil, and spark plugs have all been replaced. The O2 sensor heater has been dead for years, and the ECU is still reporting that so I think its safe to assume the ECU is undamaged. We did, for no apparent reason get the car to start after replacing this stuff, only to have it die after attempting to set the engine timings. Now it has no spark at all. We tested the coil and ICM again with parts of a friend's car and the car still will not start. We are at a loss as to what else it could be.

Install those new components in a genuine Honda distributor housing and the problem will likely be solved. Be sure to disconnect the negative battery cable, prior to working on the ignition system. If the CEL comes on and goes off normally, when the ignition switch is turned to ON (Position II), then the internal distributor sensors (CKP, TDC, and/or CYL) are likely bad. These distributor housings tend to only last 50,000 to 95,000 miles.

Here's how to replace the oxygen sensor:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563.html#post223376

Do the internal distributor sensors (CKP, TDC, and/or CYL) show up with an error in the ECU diagnostic check?

The new components were replaced in the original housing. The physical distributor is still the same.

Not usually. It's just like the situation where failing ICMs and coils don't usually throw a code.

We have now at this point replaced the distributor and still have no spark.

. Test all under hood and under dash fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-3.html#post252145

. Was it a new genuine Honda distributor housing?

. Perform tests, in Sections 1 and 2, if the problem persists:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-2.html#post229012

I have a '93 Honda civic.

What would happen if one was to unplug and replug a spark plug wire out of and back into the distribute cap? That would then result in the engine not starting with no spark.

The ICM, Coil, Spark Plugs, Spark Plug Wires, Distributor Cap, and Rotor have all been replaced.

I can confirm the power is getting to the coil, the rotor is turning, the fuel is getting to the chamber (meaning not Main Relay, fuel filter, or fuel pump), and the ECU is working.

All checks on the distributor, check out. A different distributor was tried and still the same problem.

Any new ideas would be helpful. Thanks

Maybe something got unplugged when unplugging Ignition wires.
Was it the Coil wire or a cylinder wire?

It was a spark plug wire. The #2 Cylinder. I'm pretty sure it wasn't that anything else was unplugged. The distributor is pretty prominent in this engine and not much is around it.