Excellent reply by pat, i agree. Also, don't be afraid to raise mold temp. (230-250 F) or so and maybe try slow to medium inj. speed. Also, I would be very cautious of high screw speeds, and excessive regrind rate if applicable. Definitely dry mat'l (180 F). Good luck!
Delrin can be molded easily. However, be sure the molder has capacity to run a heated mold (250 F). 100P is great for thicker wall parts but 500P which is a lower melt index, works better for thinner walls and I have had better luck in maintaining tight tolerances with it.