Date: Sun, 22 Jun 2003 16:25:26 -0700
Reply-To: Tom Young <tomyoung1@ATTBI.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Tom Young <tomyoung1@ATTBI.COM>
Subject: Re: Confused about valve adjustment
Content-Type: text/plain; charset="iso-8859-1"
I haven't been following this thread, and really don't know anything about
water-cooled engines, but this seems like a more general distributor issue,
so I'll jump in.
The distributor spins around telling each plug when to fire. Everything
else being equal (it hardly ever is, in real life) as long as the
distributor is saying "fire" to each spark plug in proper order and at the
proper time (i.e., so many degrees before or after TDC) its orientation
hardly matters. So, if the firing order is 1-4-3-2, then when the rotor
points to the wire leading to the #1 cylinder the #1 cylinder should be
ready to fire, i.e., near TDC on the compression stroke. The distributor
then moves on to the next wire, which should go to cylinder #4, then #3, and
finally #2.
Orientation is:
#3 #1
#4 #2
If this "basic" setup is correct, then rotating the distributor, i.e.,
loosing the clamp and rotating the distributor slightly one way or the
other, is affecting "timing", i.e., *when* the spark plugs go off in
relation to TDC.
Now, I don't think I *could* insert the distributor in one of my air-cooled
vehicles 180 degrees off from its "proper" orientation because it has a big
old vacuum canister hanging off one side and a very tight spot in the engine
where it lives; there just wouldn't be enough room to get it seated if it
was rotated too far one way or the other. Maybe it's different with the
water-cooled beasts.
So, for the moment at least, satisfy yourself that the basic orientation is
in order. I find that with a good light and just a little straining I can
see right down the spark plug hole and into the cylinder; this is
particularly easy with cylinder #4. If I was confused what I would do is:
Remove all the spark plugs.
Turn the engine over by hand (fairly easy with plugs out) looking down the
spark plug hole until the piston shows up.
Rock the engine back and forth when the piston is right near TDC and you'll
be able to establish, very closely, when the piston is *at* TDC. (Actually,
being right *at* TDC isn't all that important for what we're doing here, so
don't sweat it.)
Check to see if you're at TDC for the compression stroke (spark plug should
fire right around here) or TDC of the exhaust stroke. You do that by
checking to see that both valves are closed; if they are you're at TDC of
the compression stroke. (I have a good enough view through plug #4 that I
can see the valve heads themselves. If your view isn't as good just look at
the valve stems/rocker arms by removing the valve cover. It should be clear
when the valves are closed.)
Remove the distributor cap and look at which spark plug wire the rotor is
pointing at. Is it the #4 wire? If so, check the orientation of the other
3 wires; the next wire clockwise should go to #3, the next to #2, and the
next to #1. If they're not in this order, rearrange them until they are.
Having gotten *that* out of the way, you can then work on your valve
adjustment. Since you know #4 is at TDC of the compression stroke, set it.
Then rotate the engine so the rotor is pointing at the #3 wire, and set that
cylinder. Rotate the engine again 'till the rotor is pointing at wire #2,
set that one, and so forth. Except for cylinder #4 where you were peering
down the spark plug hole, you probably *won't* get the piston *exactly* at
TDC this way, but the lifters are riding on the "back" of the cam at this
point and you have wide latitude here: screaming precision isn't that
important.
---------------------------------------------------------------
Tom Young '81 Vanagon
Lafayette, CA 94549 '82 Westfalia
---------------------------------------------------------------
----- Original Message -----
From: "Dan Erlandson" <danoer1@ECLIPSE.NET>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Sunday, June 22, 2003 2:55 PM
Subject: Re: Confused about valve adjustment
> on 6/22/03 5:22 PM, Dennis Haynes at dhaynes@OPTONLINE.NET wrote:
>
> > Upper left is usually #3. 1 nad 2 are on the passenger side. 3 and 4 is
> > on the driver's side. 1 and 3 is in front.
> >
> > Dennis
> >
> ok so since my notch in the distributor is on the upper left as you look
at
> it from behind the van, it seems to me that when "they" replaced the
> distributor a few years ago they installed it 180 o reversed.
> I have tried starting the van. She cranks but doesn't catch. I've
changed
> the wires to be 1,4,3,2 and so if the distributor is out of sync then...
???
>
> Can I just loosen the screw for advance/retarding timing and pull her out
> (at TDC... but where is TDC if the distributor is out) ??
>
> Help!!
>
>
> --
> Dan Erlandson
> Flemington, NJ
> > danoer1@eclipse.net
> 91 VW Vanagon GL 170,000 mi
> 99 VW Passat 107,000 mi
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