My intake manifold has black gunk in it. Replaced the TPS and IAC today and found out the intake has carbon in it. This looks just like a stuck open EGR valve. Can I block the EGR valve or do I need to replace it?

The vehicle is a 1992 F-150 reg cab long bed 4x4 5.8

 

I think that is typical because of the egr working the way it's supposed to. The manifold needs cleaning periodically and the egr passages need cleaning.

 

After a little further review. I found oil in my air intake. All the signs lead to clogged PCV valve. Soaked breather, oil in intake. Oil blow by in intake, that with the EGR gasses makes it look bad. I hate what a bad $2 part does.

 

Or it could be that the rings aren't sealing as well as they used to. Modern engines have low tension rings to start with for fuel efficiency. Some people put catch cans in the pcv line to keep the oil from getting to the intake.