PJAX still requesting full pages?

PJAX is most likely timing out because your app is too slow and that's a whole other problem.

Try this on for size:

$(document).on 'pjax:timeout', ->
    return false # inifinite timeout! get out your favorite ajax spinner!

$(document).on 'click', 'a[data-pjax]', (e) ->
    e.preventDefault()
    return $.pjax.click(e, '#content')