Shuts off while driving and idling and not starting, check engine light on

Car would cut off while driving and when idling and would start back up after an hour or so. Then it got to where it took hours to start. Diagnosis said change main relay so i purchased that. It still wouldn't start. Several mechanics said it wasn't getting fuel. I didn't hear the fuel pump running so i've been trying to locate the fuel pump relay with no luck. Located the fuse but no relay. The car's information display says 'gearbox malfunction' and the check engine light is on.