I pulled off the Upper and lower intake manifolds saturday to clean the "6-ports". Found that 2 of the intake passage ways in the extension manifold and the attached ports in the lower intake manifold were coated with black crusty crud. The other 2 passage ways were nice and clean.

Anyone else have this? Anybody know what would have caused it. Normal or the sign of something not right?

The 2 that were dirty were the same 2 that the secondary injectors sit in. The air bleeds was all caked with the crap too.

 

I got the same thing. The engine I tore down had 120K on it, so I'd assume that's normal.

 

ya my secondary runners were the same way

 

I am glad to find out that I am not the only one getting this.

Does anyone know why it only happens to the secondary ports?

My secondary throttle plates seemed to be opening a little late and it may have been a factor (I have now corrected it).

I also wonder if eliminating my EGR valve would help.

 

Totally normal, it is not a problem. The build up is the gunk from the fuel sprayed by the secondary injectors.