Hey guys i have an 88 firebird formula with a 5.7l.
In the morning the car starts right up but after letting it sit off for a few min the car barely starts up. When it finally cranks enough times the car fights to startup and there is alot of smoke and a huge gas smell.

My question is if it is a bad injector how can i find out which one it is?

 

with a fuel pressure gage hooked up and the return line clamped off, pressure the fuel rail and then clamp off the pressure hose and watch the gage. it should hold unless there is a leak in the fuel rail.
if you have 1 bad injector, the others won't be far behind.
for the price for a set of remans from southbay or injectors plus, replace them all.

a leaking fuel pressure regulator is also a possibility. the regulator is normally easy to check, just pull the vacuum hose and look for signs of liquid fuel. be sure to cycle the key on to pressure the system up.
sometimes the regulator will only leak intermittently, so you may need to cycle the key on a few times and watch it for a couple of minutes between key cycles.

to check for lindividual leaking injectors, pull the fuel rail and pressure up the system and look at the injector tips.
if it still has the factory injectors and if your going that far, again i would recommend just replacing all of them and the regulator.