Truck died and won't start

is it carberated or fuel injected

Its a 2000 chevy 4.3 l truck I'm thinking fuel injected but it has some type of carbarator

does it say EFI on the top of the engine

I don't think so i am not near it but if this helps it has a pressured fuel rail and i pulledof the breather tube andput gas in it that's how i got it started

Its called a throttle body and just because you can hear the fuel pump running doesn't mean its good it has to have a certain amount of pressure to push fuel through the injectors that engine has a check valve borrow a fuel pressure gauge and check your fuel pressure

I replaced the headers on my 1995 Chevy Cheyenne - runs until I put the breather on now wont start....pulling my hair out