My Porter Cable brad nailer just quit. Gives a weak wheeze when I pull the trigger. It had been working fine, then shot a brad weakly, then only the wheeze. Air pressure is good, PC air stapler works fine when I attach that. What's wrong?

My Porter Cable brad nailer just quit. Gives a weak wheeze when I pull the trigger. It had been working fine, then shot a brad weakly, then only the wheeze. Air pressure is good, PC air stapler works fine when I attach that. What's wrong?
Did you ever oil it?