Start up.

Start up. Having issues on cold start up . E38ECU, GM gen IV, 363 stoker, 212/216 114+4 cam, LSXRT intake, 775cc FIC injectors, 103mm Granatelli TB, DW return fuel system.

First start up the engine starts grate RPM climb to 1700rmp then drop to about 1000rpm which is about 200-300rpm below target then drops again to below 500rmp and dies. are these drops caused by the ECM switching where it gets info from? Why can I make the commanded rpm is it commanding too high? I not that the wideband is also reading lean during this process. Is cranking FA mult stage the only place I can add fuel for this or is it using a different table at that point? I have tried adjusting base airflow & cranking FA and it has gotten better but seems like it has hit a point where has started to make no change. Should I be logging something else?

Sorry if this question seems stupid but this is my first vehicle.