I know this is just about my individual bird, but I thought maybe it'd help a bit?
I have a Jenday Conure who I bought only 5 weeks ago. She is 1 year old and was completely parent reared and untame. She now hardly ever bites, will come 'UP' onto my hands and snuggle with me. She absolutely loves kisses everywhere especially on her head, and is now starting to like and accept scratches from my fingers everywhere on her body.
I spent [and do spend] a few hours each day sitting down outside her cage and talking to her. Then I'd get up, still talking to her, and go about my daily business. [I have her in the main room where my small family always is]. When she bit, at first it was because she was absolutely TERRIFIED. So i kept my hand where it was, didn't flinch... when she stopped biting I'd move my hand away.
After about 2 weeks, she wasn't afraid of me anymore, and her biting had gone down a lot, but then she decided to just be plain naughty and bite me again. So, seeing as her biting wasn't out of fear anymore.. i told her "No." in a very VERY deep low serious growly voice, glared at her into her eyes a little and tapped her beak lightly. Her expression changed instantly. She knew she'd done the wrong thing and it was almost like she was thinking "Darn.. I didn't get away with it!"
She hardly bites at all now.

And absolutely LOVES being out with everyone. I believe your bird just needs some space. Let him know you aren't going to hurt him. Trust is the NUMBER ONE thing to build up with a parrot. He'll come around I'm sure.

~Kinny