So I just got in my car (89 base model) and about two miles down the road, the engine suddenly acted as if the throttle shut off. The engine was still turning while in gear but died as soon as I pushed the clutch.

I coasted it to a parking lot and did basic troubleshooting. The throttle cable is fine, the battery has good voltage, engine turns over smoothly. The fuel pump is priming and I can smell fuel at the dpfi.

Also, the main relay is about three months old, genuine brand new Honda OEM part. The timing belt still had tension on it also. I'm lost as to what would hit so suddenly and completely stop the car from starting again.

 

Sounds like you still have fuel so you need to check if you are getting in spark out of the dizzy. Could be a bad coil or igniter.

 

Damn. 2 miles down the road and it dies
Did the seller drive by and wave haha

Happened to a 96 civic I had
25 miles later after mean off ROADING tho
Rotor and cap was dirty

Check if you have spark as mentioned above.
Hold spark wire to battery negative and have someone crank
If no spark clean the cap and rotor
If still no spark
Try a known good distributor
If spark occurs and no start
Run compression test
If test checks out
Check timing
If compression test doesn't show good results.....
...May your civic rest in peace.