1994 gmc safari engine problem

94 safari 4.3L v6 will only start and continue running when the gas pedal is held about half down.seems to be flooding,was fine one day then acted this way the next day it was started.could this be egr?if not what else could it be

This is either a TBI or a CPI injection setup, my first step would be to look down this things throat and see what is happening, perhaps a part fell off.