stalling problems after initial start up on 1992 GMC Vandura 3500

it starts runs for about 15 seconds then the injectors spray only intermittently causing the stall. if we try to start it again it won't unless we cycle the key. we do not have a fuel pressure gauge but the recent work I had on the van included a fuel pressure test which was "within range"

possible fouled injectors.
rec. fuel system clean. ethanol treatment to 1 tank premium fuel. result may take drive time.