Fountain solution too acidic
Reduce amount of concentrate, or switch to less acidic solution.
Conductivity is too high
Dampener setting is too high
Reduce dampener setting
Too much drier added to ink
Replace ink. Overuse of dryers can cause the exact opposite result.
Running too heavy of an ink film
Lower ink setting. Switch to stronger pigmented ink to achieve desired density with thinner film.
Using wrong ink
Consult ink manufacturer.
Rollers are contaminated
Make sure all solvent is removed from rollers before inking up. Clean / deglaze rollers.