1986 Toyota Corolla Dirty Intake Manifold

You bring to light something I don't know how to adjust and that's the carburetor. I have yet to fire this old engine back up, and I haven't replaced the old o2 sensor. I don't know if the o2 sensor is a recent replacement, as i've just gotten the car.

My main concern for many engines is the fact that the inside of intake manifolds get so crusty and sooty. Doesn't that mean some sort of putrification within the engine case? It probably does, so my next question is: what section of the engine block are likely to be dirtiest in a Toyota 4A-C 1986, or for any aging gas engine?

This vehicle was running when I first received it. I am still in the process of cleaning out the manifold, and will inspect the combustion chamber next. Guaranteed 2 Pass cleaner from Kragen was used once on this car.