I recently bought a 1986 Trans Am with the LB9 305 TPI and I've been trying to figure out why exactly it won't start. It'll fire on the first crank and then completely flood and refuse to fire any more. There's a strong gas smell as well, so I'm certain of it's flooded state.

What I've tried:
Unplugging TPS, MAF, various injectors.
Inspected the fuel pressure regulator (the diaphragm appeared to be perfect and the regulator itself looked fairly new).

Can anyone offer some advice? Thanks!