Sean, If the fuel pump doesn't run, naturally it won't start. Check the connection on the inertia switch. If the connector heats and the plasic swells, the connector will lose contact. The RPM relay could also cause the problem and the pulse coil could be over heating. The pulse coil activates the RPM to close contacts and power the fuel pump to run. Sounds like something is heating up and your losing contact. John Hervey