E.R.
If he has a sleep deficit, then you can try getting him to bed super early (like 6 pm for a couple of nights).
Also, watch what he is eating for clues. Keep a food journal maybe. I know for example if my son has ANY thing with blue food coloring (read labels, it's even in marshmallows!) that he goes off the wall within minutes. McDonald's will do this to him, too. Something in the seasonings, maybe? We only get fast food on special days and I notice a huge change in him and he also has a hard time sleeping then.
Also, does your son have any allergies? He might not be getting good sleep if he does because of night waking due to allergies. Think about that and make sure he bathes right before bed and has a clean and dust free room.
These things should help. There is also a homeopathic remedy from Hylands, Calms Forte for kids, that helps my ds fall asleep at bedtime.