[HoodStrype]

I three had the same problem, however fixing my vacuum leaks didn't work- I had just put a 1" spacer on my intake and it started. Turns out she wasn't getting enough fuel. If you haven't added anything it would most likely be a vacuum leak or kink in a vacuum hose.
The main ones on my car that were bad were the one going to the Fuel Pressure Regulator, the one going to the charcoal canister, and my intake gasket had broken when I put the new one on. If you do hear a hissing noise, spray carb cleaner around with motor running until you hear it stop... that's your leak!

PS: Carb cleaner and paint DO NOT MIX...