The sliding door on my '90 Vanagon continues to behave badly. Push down on
the door handle, inside or out, and it juts open but doesn't "pop" or
"spring" open the way it's supposed to, so it can make that nice long slide
backward.
For starters, I replaced the locking mechanism at the back of the door (the
old one occasionally loosened). When that didn't fix the problem, I
thoroughly cleaned the tracks, above and below, with degreaser and cleaner
and wiped them out. I have sprayed WD-40 on all possible sticking points and
worked the thing. Tried a little white grease on the hinge. While everything
seems to improve it slightly, though only for a while, nothing seems to bring
back that wonderful pop-out effect the door is supposed to have.
   I can't help but to think there's a spring-open mechanism that isn't
working. At the top of the black U-shaped hinge, on the side where the door
hangs on, there is a fat spring just sitting there, beneath the pin that
keeps that who assembly assembled. Is it supposed to somehow tighten when the
door closes and spring open when the handled yanked down? I've tried to
figure out if there's any evident way it could provide that kind of springing
action, and just don't see it there. Any one got any clues about what
mysterious force provides the ooooompf to pop out the Vanagon sliding door?
Any suggestion is appreciated?  I'm about to take this problem to a nearby
Vanagon specialist--but I really thought I could fix it myself (with a little
help from my friends).

Thanks--

Don Oldenburg
McLean, VA.