mx3 1.8 v6 carbon fouled spark plugs causes?

[Dakota]

I have a 1993 mx3 v6 1.8l. I have gone through 3 sets of spark plugs because they have become carbon fouled. The timing is set to 10 degrees and it idles at about 1100 rpm with the idel screw all the way in. Anyone else have this problem or know what it might be?

 

[stevesei]

Hey! Did you solve your problem? It sounds very much like a vacuum leak to me. Had you just changed valve cover gaskets? If so it's common to miss the large air breather corner hose on the back of the rear head, passenger side. The idle screw show be good at 2-3 turns out.