I have a 1990 honda civic that won't start after being driven for a while then after the engine is turned off it won't restart ( turns over just won't start ). Such as being driven 40 minutes and stopping for gas. After car sits and cools for a few minutes its starts right up. Could it be the igniter or the coil? No warning lights come on when this happens.

Replace ignitor and coil:

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

If problem persists, focus on the main relay (less likely).