I've got a 2002 Nissan Almera Perfect 1.8L MTX on which the hood only opens if I pull up on it while someone else yanks the hood release lever.
If I manually set the latch with the hood up, then pull the lever, the latch releases properly every time. It's only when the hood is in place that the latch has trouble releasing.
Here's what the latch looks like:
It's in the latched position here. Just to avoid any confusion, the latch was bolted back in place during all my tests.
EDIT 16/6/2017
I tried working some WD-40 style oil into the mechanism, and while it was clearly is operating more smoothly, the hood still won't open unless I pull up on it while someone else pulls the release lever in the cabin. Is it possible that maybe the spring has just gotten weak and doesn't have enough strength to push the hood up when the lever is pulled?
Anything else I can try, or should I just head to the junk yard for a replacement latch?