It may need cleaning.

You should clean your fountain pen at least every two months if used daily. Use lukewarm water only, never hot water, ammonia or any other type of cleaner. You should remove the nib section and flush it under a stream of water. If it doesn't flow clear, place the entire nib section in a paper cup and let it soak at least overnight. Rinse the next day. Still not rinsing clear? Give it a second day. This will usually take care of any residual ink. After a few times cleaning your fountain pen you will acquire a feel for each pen's needs.