My 91 Honda accord will start fine when cold. Sometimes and only sometimes, after driving for a while it will not start. The starter is not bad because it turns over, it tries to start and sometimes almost does only to die. After about 5 minutes or so it starts again.
Sometimes the idol will kick down substantially when at a light. Then it will correct itself. It has also died on me while coasting to a stop in neutral. Sometimes it restarts right away and other times it takes a few minutes. I have replaced the speed sensor, the fuel injection relay, and had a severe tune up including the works. Still it persists to do this.

Replace the Ignition Control Module (igniter) and coil in the distributor. I believe this will solve your problem.