Similar to the 1998 civic that won’t start, my 2002 Civic will not restart 100% of the time after initially starting it from the overnight parking, then needing to restart after a short stop. It seems to be entirely random and everything else checks out - there is gas, the starter turns, the battery is goo, etc.It just won’t catch, sometimes for a short time, sometimes longer. Of course, the extended warranty just ran out and we were not able to get it to a dealer under this condition. Any clues? Are there hidden warranties on this issue? (We’re in Canada.)
Most of these kind of problems are either due to a problem with the ignition or the fuel system. Checking to see if the plugs are getting spark while the trouble is happening is a good thing to check. You could also spray some stater fluid into the intake to see if that helps fire the engine that is having a problem with fuel delivery to the cylinders. The tank may be full but the fuel still may not be getting to where it needs to in order to fire the engine.
If there is a fuel problem it could be the fuel backflowing into the tank due to a bad check valve in the fuel line. Also replacing the fuel filter may help here.
Check with Honda about a recall replacement of the ignition switch. If it’s covered by recall, there is no cost to you for the part or labor, for a new ignition switch.