1990F150 Fuel pump floods engine at start

First ever post so here's hoping. On start-up the fuel pump on my '90 F150/302 auto does not let up. It just pounds the gas in. I've changed the EEC relay, the Fuel Pump Relay, and the fuel regulator valve. Short of an insurance fire I've tried everything I could think of, not that I'm that smart anyway. Any help would be appreciated. Thanks.

Changed out distributor, relay, remote fuel-pump switch, tank and center. Touched a small relay attached to the distributor wiring harness and now it runs. Does anyone know what the small, grey plug on the 1990 F150 distributor harness is for?