Check the distributor cap. Pull it off and clean the rotor & contacts w/ some scotch brite or similar.
I had this happen to me from letting a car sit up, i could start it w/ fluid and it had enough spark to keep it running but it just couldn't light off the gas by itself.
'93 Coupe>LQ4 6.0, Fast Intake, Texas Speed Cam, Mach 1 wheels, mostly stock...
'67 Coupe>CPP mini kit, '13 GT 13.2" brakes, AJE 8.8 rear subframe and a big pile of parts next to it.