'87 IROC, 305...I'd turn the car on and it'd run for no longer than 2 seconds and immediately shut off. The only way it'd keep running is if I kept my foot on the gas. The guys at AutoZone said it's the fuel pump but my father says it can't be, otherwise it wouldn't even run (even with my foot on the gas). I just changed the fuel filter, and it actually runs on it's own now, but it still feels and sounds like it wants to shut off, sounds kinda weak. I feel like it's the injectors, any ideas? What would be next in line to check/change? (On that note, what's the overall best fuel system cleaner? I've heard Lucas...what about Royal Purple?)

 

Fuel pressure regulator failure. I had the same problem on my car.

 

Verify by checking the fuel pressure. And never hurts to check for codes.

 

Thanks for your help! Much appreciated!