1988 Chevy Monte Carlo Fuel Problem?

I just did a full tune up on my car and drove it home and now it won't start. My car turns as to turn on but won't fire up. But when I pour gas into the carb it turns on for as long as I keep giving it gas. So I'm guessing It's a fuel delivery prob what could it be. Loosend line at fuel Pump and it throws gas out so I know it's pushing gas. Buddy says they could've put wrong filter in or put in wrong. Please help It's a 5.0 H.O. V8 completlly Stock.