Well Buzzard first let me warn ya, this WILL become addictive!
So you learned something from the last hunt with the sun and where you set up at. As long as you keep learning and having fun its all good!
Once they start with the warning barks it is all up hill from there. I have seen on video where a guy just mirrored what the coyote was doing and got it to show itself for a long shot but I don't think it happens to often.
Like rickyrick mentioned, make sure you mind the wind. One whiff of human and the game is over! They also can pick up any movement from quite a ways away. I'm not sure how these coyotes busted you but they did. Actually, its is possible only one busted you and the other was just spreading the word.
If I was in that situation I would either try to mimic them or try a ki-yi or pup distress.
Stay at it and most of all keep learning. If at all possible find a mentor to show you the ropes. It will speed up the learning process dramatically!
Good luck and keep us posted on the progress.