96 Blazer cranks but wont start
 

So my blazer finally died on me the other day. first what was happening was it would take about 5-6 cranks before it would start, once it started it ran fine. then a day later it took about 10-12 cranks and it caught. yesterday i went out for lunch and when i went to start it again it just cranks for days and doesnt start. I thought it was the fuel pump cause i wasnt hearing it kick on anymore so i replaced that. After i replaced the fuel pump it still wont start, just cranks.

I did a little troubleshooting and here is whats happening. Fuel pump turns on, when you press in the vent on the fuel line in the engine bay, plenty of fuel comes out. When i spray some starter fluid in the throttle body it will start and run for a second and then dies.

What could this be? starts with started fluid so i should have spark, and fuel is getting to the inspection vent. but it just cranks and doesnt start.

no one? not even a guess?