Matt Ion wrote:
> This should initiate some good debate...
>
> I've always understood that ignition timing should be set with any
> advance systems (vacuum diaphragm, etc.) disconnected. I tried to set
> up my '87 Accord that way, and I can't get anywhere near the 20-degree
> timing mark with the vacuum advance disonnected. Leaving the vacuum
> line attached, it jumps right close to the 2-degree mark and seems to
> run well, if missing a little "jump". Oddly enough, when I accidentally
> took a test drive while forgetting to reconnect the vacuum line, it seem
> to have a lot better pick-up when I punched the gas...
>
> Anyway, I'm looking in the shop manual... the directions say to
> disconnect, test, and then plug the vacuum lines, then goes on to list
> the proper timing settings for various engine/transmission setups, never
> specifying that one should reconnect the vacuum lines, and describes how
> to adjust the timing by twisting the distributor. So far so good...
>
> BUT... all the diagrams show the vacuum lines still attached... AND the
> next step tells how to check the cold-advance operation (on engines that
> have it), while the following step THEN tells you to disconnect the
> vacuum hose(s), plug them, and then check the timing with an advance
> meter, listing way lower advance settings than the previous chart.
>
> Example: the first chart
> (http://moltenimage.com/freebies/g3ac...rical/24-4.JPG)
> shows that the A20A2s should be anywhere from 10+/-2 to 20+/-2 degrees
> (depending on variant and transmission) - it doesn't specifically say
> the advance lines should or shouldn't be connected, but you see in an
> earlier step that they have been disconnected and not reconnected.
> Meanwhile, the subsequent step
> (http://moltenimage.com/freebies/g3ac...rical/24-5.JPG)
> says after disconnecting and plugging the hoses, all A20A2s should be 4
> degrees.
>
> So what's the story? Experience indicates that timing should be checked
> and set to 20 degrees (there's an actual "20-degree" mark on the
> flywheel) WITH the main advance line connected. Old-school knowledge,
> however, suggests that the line should be disconnected and plugged, but
> when I do that, it's impossible to get anywhere near 20 degrees (and
> really, old-school knowledge suggests that 20 degrees BTDC is an
> *insane* amount of advance for ANY engine).

matt, if the honda factory manual says disconnect, then you disconnect.
end of story. and who are you to judge 20 degrees? you've got two
vacuum diaphragms iirc, both affect timing when connected, and their
subsequent movement produces the correct result for that engine. it's
real simple.

>
> I've seen this topic generate a lot of debate on a couple boards over
> which is the proper procedure... just wondering what the concensus is in
> these parts?
>
>
>
> ---
> avast! Antivirus: Outbound message clean.
> Virus Database (VPS): 0541-4, 10/16/2005
> Tested on: 10/16/2005 8:09:48 AM
> avast! - copyright (c) 1988-2005 ALWIL Software.
> http://www.avast.com
>
>
>