Date:         Fri, 4 Feb 2005 14:55:29 -0500
Reply-To:     "Daniel L. Katz" <katzd54@YAHOO.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         "Daniel L. Katz" <katzd54@YAHOO.COM>
Subject:      Re: Cold start 3 cylinder stalling and bucking idle insanity!!!

adam:

set your analog meter on a sensitive voltage setting and check for a
needle movement as you shunt across from engine to body, especially from
engine to ecu case, with the engine running - this is the acid test. also,
while cleaning the terminal surfaces is a good idea, the weak point on
that bonding strap is the crimps, and it is possible to have several ohms
or more contact resistance at the crimp itself - easy to check with strap
disconected using a good meter. as a quick and dirty test, you could use a
good set of jumper cables with jaws that really bite to temporarily make a
known good bonding connection between body and engine, and also bewteen
oxygen sensor housing and body (ecu) to see if that helps.

we have an '84, which has a zillion individual wires from the ecu that are
grounded next to the braided strap you are working on. there was a big
contact resistance on the engine side crimp of the copper braid
(8 ohm !!!!), and so i crimped and soldered a new ring terminal on each
end the braid, and then also bundled all those individual ground wires
together, freshly stripped, and crimped and soldered them using a single
new ring terminal.

dan




On Thu, 3 Feb 2005 00:54:04 -0500, Adam H. Behle <tikiman2@COX.NET> wrote:

>I forgot to add that I also cleaned the grounds with a dremel/wire brush
on the left head and
>firewall, but it had  no effect.
>
>On Wed, 2 Feb 2005 23:44:51 -0500, Adam H. Behle <tikiman2@COX.NET> wrote:
>
>>It seems like more and more Vanagonites are having this problem more
than ever these
>days.
>>My 87 Westy with 156K miles has the evil cold start bucking and stalling
problem as well.  It
>>feels like it is running on 3 cylinders and stalls repeatedly.  Once it
is warmed up by careful
>>manipulation of the gas pedal for about 5-10 minutes, all is well-great
power, throttle
>>response, 17 mpg.  Exhaust smells a bit rich, but it has for quite some
time.
>>
>>This is what I have done so far:
>>Replaced air filter, fuel filter, oil, oil filter, and spark plugs.
Found and replaced 2 broken
>>vacuum lines. Checked throttle switch per Bentley and found it to be ok.
I have a nicely
>>humming idle control valve which was cleaned anyway.  Swapped out the
idle stabilizer
>>control unit with a friends' and got no change in behavior.  Replaced
temp 2 sensor last
>year,
>>but still need to re-check it.  All this has resulted in no change of
cold idle stalling/bucking
>>behavior.
>>
>>It seems like the fuel pressure regulator could be suspect, or possibly
the "new" temp 2
>>sensor.  The oxygen sensor doesn't participate in the cold idle loop
anyway, so that is
>>probably not to blame-right? It was replaced about 40K miles ago. My air
flow sensor had
>the
>>"capacitor fix" when I was hunting down Vanagon syndrome a few years
back. Turned out to
>>be the ECU, which was replaced.
>>
>>So...I am at a loss for what to do next before giving up and bucking
over to my mechanic.
>>Any last ideas???  I'm not ready to give up just yet!
>>
>>Thanks, Adam