Don't let the wet look fool you,the crankcase vapors also flow through the same area.
If the E.H.A. is leaking the wet spot would be on the outside.
In the the case of rough idle the first things to check would be,
engine tune up w/correct plugs,o2 sensor/lambda,vacuum leaks.
If all these are in order pull out the injectos and have them tested for proper opening press. and spray patterns.