<VV> ignition timing problem on a 110

[Marc Sheridan]

Larry and the rest,
The pinging in my car has gone away and with the VA hooked up!

Larry Forman's advice to test the VA with a Mity-vac was all the motivation
I needed to go out and buy a Mity-vac :o). ("Never miss the opportunity to
buy a new tool.") As Larry suspected, it started to move with about five
inches of vacuum. Then I proceeded to bang on it with a hammer and deep
socket until it didn't start moving until it had 10-11 inches of vacuum.
Hooked it back up and during the test drive I could bog it as much as I
could (wot in 4th @ 10 mph)and still got no pinging.

If you missed Larry's procedure for "restoring" the VA, it is at the bottom
of this post. He adds that I need to check the VA with a timing light, which
I plan to do later, but the quick fix worked to rid me of pinging.

Thanks to all who replied to my request for help.

Marc Sheridan

From: "Larry Forman" <Larry@Forman.net>

> At 02:40 PM 7/17/2004 -0400, Marc Sheridan wrote:
> >Recently, I WAS having a problem with pinging. The car is a '66 110/4 and
it
> >was very hard to start from a stop without pinging. It was like starting
in
> >second gear. Plus, it would also ping when slightly bogged while going up
> >hill or being in too high a gear.
> >
> >Now it runs fine, no pinging and easier to get moving from a stop. What
> >perplexes me is the way I fixed it. I simply disconnected the vacuum
> >advance. The car has an almost new Dale distributor, Pertronix II and the
> >timing is set at 14 degrees BTDC.
> >
> >So, is this a proper fix or am I masking the real problem? Thanks for
your
> >comments.
> >
> >Marc Sheridan
> >'66 Monza 110/4
>
> Hi Marc,
> I think you know the answer, which is you ARE masking the real problem.  I
> suspect that your vacuum advance cannister's internal spring is VERY weak,
> which is what I see in nearly every one of these that are original.  You
> can likely "restore" it to proper operation by first checking if the
spring
> is weak.  Take a hand vacuum pump, like a Miti-vac and see if the arm
> starts moving before about 9-10 inches of vacuum, which it should not.  I
> bet it starts moving before 6 inches of vacuum.  If so, it would provide
> too much advance under high vacuum conditions, like light throttle
> acceleration.  So, remove the vacuum advance canister and place it into a
> vice or set it up between two bricks so the arm hangs down. Then take
> either a 9/16 or 5/8 inch deep socket and place it on the end over the
> nipple.  Bang on the end so it compresses the internal spring and then
test
> to see if the starting vacuum has increased.  Keep repeating until you are
> at the right place, then reinstall and test drive.  It should work much
> better after the "restoration".  If you alternate between the two sockets,
> you can compress the end and it will look almost like it was built that
way
> and worker properly.
>
> Additionally, you can take one of those new advance timing lights and
> calibrate the vacuum and mechanical advance characteristics with the
engine
> running.  With a new Dale distributor, you should be in excellent
condition
> for mechanical advance, but check and compare with the information in the
> CORSA Tech Guide. It provides information on the vacuum and mechanical
> advance characteristics for most Corvairs.  Pretty valuable information.
>
> -- Larry