When they start to bark at you.. Hit them with about a good solid minute of the coyote pup..Then stay silent for about 8 minutes..
It could be your cover scent too.. Many of us no longer use cover scent. Me personally I put an object on the side I am calling so they have to make their arc to come into the wind on the other side. Maybe a barn, house, equipment. stream, big rocks. See I do understand that it could be your hunting in the boonies and you don't have things in fields to use to make them come in from other sides. More and more I have seen coyotes coming in also not on the down wind side.. I have seen them coming in to the call taking the least resistance.. In many cases the county roads itself.. They also will Flank you from the sides.. Your looking down wind and there they are staring at you from the sides..
Black coyotes nice trophies... I have called in black coyotes in Clearfield/Centre county area and saw one run cross the road right in front of the NE Pa Turn Pike Exchange at Bear Creek..
How long are you doing the actual calls? Are you leaving big gaps of silence in between?