Interesting. I have this same engine only with Alpha but never had this happen so I'll be following with interest. To confirm you turn the key, let it sit and a 1/2 minute later the fuel pump kicks on? And finally after the pump starts running it never shuts down? Just wondering if you don't have multiple issues. Could be a bad ignition switch. Are you giggling the key when trying? If the pump doesn't shut off could it be flooding the engine? The pump not shutting off is beyond my knowledge but I know three inexpensive things to do keep this engine running that plagues it. They are 1) replace distributor cap, 2) replace IAC, 3) replace IAC muffler. And while the flame arrestor is off clean if with brake cleaner. This a starting point and could be contributing to some of the problem most likely not related to the fuel pump not shutting off issue however. My two cents.
