I just finished with my injector install on my NB and had a question about my intake manifold. It was pretty dirty inside, not sure if it was oil or fuel, but I presume it would be fuel. Is it normal for an intake manifold to have fuel stains inside? Should the be clean for the most part? I'm assuming my intake manifold has never been cleaned, and with the mileage that's on the car, I'm not too concerned (about 100k miles).

Is it normal to have a dirty intake manifold?

 

Yes. But clean it if you want.

Are you gonna make a thread for every silly question you have?
How about just make a build thread and ask all of them there?