I have a 91 Honda Civic that will shut off while driving. This just started this past weekend. First it took about 20 minutes to start, next time took about 40 minutes, next time over an hour, next time it didn't start (tried for about 2 hours while stuck on the side of the road).
What could be causing this? It is turning over but not starting. (FYI, just replaced the spark plugs) PLEASE HELP!!

Replace the Ignition Conrol Module (ICM) and coil:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-4.html#post265896