Date: Tue, 5 Feb 2002 18:53:38 -0500
Reply-To: brad barcom <bbarcom@HOME.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: brad barcom <bbarcom@HOME.COM>
Subject: High Idle Solution!
In-Reply-To: <005401c1a21a$2700d560$e78eaec7@here>
Content-Type: text/plain; charset="iso-8859-1"
I just wanted to thank Joel and everyone else who gave me help in solving my
high idle problem that has been a thorn in my side for several years.
For anybody who is suffering from a perenial high idle problem that comes on
during the colder months of the year, I strongly recommend checking your
throttle position switch. After ruling out the idle stabilizer valve, the
idle stabilizer control unit, and the temp II sensor, I finally made my way
to the throttle position switch. For those of you that are unfamiliar with
this gizmo -- and I do mean gizmo, it is a switch on the underside of the
throttle body that is on (continuity) both at idle and full throttle.
In my case, the switch never showed continuity and therefore my ECU always
acted as if I was running somewhere above idle and below full throttle,
which ironically caused a high idle. I don't know exactly know how this
switch works with the ecu, but I'm sure someone on this list can help me
out.
At any rate, the fact that this switch does not show continuity seems to
have a more adverse effect on the idle in cold weather than warm -- once
again, I'm sure someone can tell me why. When I pulled this switch out and
pried it apart, my dismay that it didn't function was replaced with a
certain awe that it ever worked at all. Truly this is one of the more
flimsy parts that I've encountered in the Vanagon, but after about an hour
of meticulous cleaning I was able to get it to do what it once did. Even
though it is now working, I think I will buy one from Bus Depot ($56) to
have on hand when this one goes again, which it surely will (by the way,
thanks Ron for the great service you offer. Even though I've bought well
over $1,000 in parts from you, I still would rather you have it than VW!).
I hope this helps somebody else who has the same problem as me. If you have
any questions please feel free to email me and I will help in any way I can.
Thanks again,
Brad
Vanagon GL 1987
Toyota Pickup 1986
-----Original Message-----
From: Joel Walker [mailto:jwalker17@earthlink.net]
Sent: Sunday, January 20, 2002 8:23 PM
To: brad barcom
Subject: Re: High Idle 1987 GL
> to change. I have also checked the resistance of the temp sensor,
but it to
> my dismay it was well within tolerances --
i've found that this means nothing ... try replacing the sensor
anyway. it's cheap and not too difficult to do. i've had the sensors
pass the test and gave up and replaced it anyway ... and the problem
went away. go figure. maybe the module gets old and needs a new sensor
or something. or bentley's temp charts are wrong (my favorite
conclusion).
> the she idles fine. However, as soon as I touch the accelerator the
van is
> once again off to the races until it reaches operating temperature,
but even
> then it never idles normally. Right now, I am running with the ABV
> unplugged.
also check the idle position switch and the full throttle position
switch (same switch on the 87's). the switch(es) may be failing to
tell the idle stabilizer module that you really are at idle .. or
worse, telling it that you are at full throttle (in which case it
richens the mixture .. which would definitely raise the idle).
> I also removed the idle stabilizer control module from behind the
passenger
> side tail light. Upon opening it up, I could see no visual burns as
others
> in this group have noted, although it did smell oddly electrical in
that
> cooked-board sort of way. However, I don't know if this really
means
> anything, as that little bi-folded board has been stuck in that
small casing
> for the last 15 years. I'd smell too if I were in there all that
time.
the best thing is to find someone with a similar year bus ... and see
if they will swap parts with you for testing. if you swap the module,
and it cures the problem, then get a new module ... $$$!!! :( same
thing with the valve.
first thing i'd do is swap the temp sensor. just put a new one in.
it's like $12-15 (get a new rubber o-ring, too ... another $1!) and in
the words of many mechanics, "you probably needed a new one, anyway".
:) then try swapping parts to determine the culprit (if the sensor
doesn't fix it). in my experience, it's usually been the temp sensor.
only once have i seen a module that was flakey.
and check the grounding wire/strap to the engine ... there should be a
large wire or braided copper strap over on the left side of the
engine, going from the cylinder head to the wall by the ignition coil.
if this wire/strap is corroded or missing, the engine is NOT getting a
good electrical ground and all sorts of strange electrical behaviour
can happen.
good luck!
joel
