Date: Mon, 25 Feb 2002 20:24:22 -0500
Reply-To: Laurence Smith <lsmith@COGECO.CA>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Laurence Smith <lsmith@COGECO.CA>
Subject: Re: 2.1 digifant MV engine Air Flow Sensor Wiring Harness 87
Vanagon
In-Reply-To: <00fd01c1be46$41476270$0100a8c0@MEDION1800>
Content-Type: text/plain; charset="iso-8859-1"
Robert,
Since you have already replaced many of the Digifant components to try
to resolve this problem, I would look hard at your ground wires which
are essential for keeping the Digifant system running properly.
Based on your list of problems, I don't think it is the wiring harness
upgrade.
The Bentley manual has very detailed wiring diagrams and the ground
wires are almost always brown or brown/black (sometimes brown/red).
Now that our vans are getting to be old aged the grounds get corroded
and don't work well unless maintained.
I have resolved several Digifant problems by fixing bad grounds.
You'll see from the Bentley wiring diagrams how important grounding is
for every electrical component. When a component's ground goes bad
all kinds of things can go wrong and often in an intermittent fashion.
Laurence Smith
Hamilton, ON
90 Westy (fanumbos)
> -----Original Message-----
> From: Vanagon Mailing List
> [mailto:vanagon@gerry.vanagon.com]On Behalf
> Of Robert Steven Fish
> Sent: Monday, February 25, 2002 4:49 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: 2.1 digifant MV engine Air Flow Sensor Wiring Harness 87
> Vanagon
>
>
> Does anyone know the exact science on this "upgraded"
> modified wiring
> harness #025-906-302 which gets installed between the air
> flow sensor, and
> the old wiring harness connector?
>
> Indicated in the tech bulletin is that "after prolonged
> driving at constant
> speed the vehicle may on occasion experience a deterioation of
> performance... hesitation or surging".
>
> I had noticed that when driving at highway speeds, the
> power would seem to
> just disappear, for a second or so, and then come back.
> This coupled with
> some rather insane idle "situations" leads me to believe
> that there is a
> defective componant somewhere in the "idle / air flow /
> throttle" system.
>
> Several years ago my Vanagon (1987) would start up
> normally, and almost
> immediately, or at the first stop light, would rev up (on
> idle) to around
> 2500-3000 RPM.. for no apparent reason. I would then turn
> it off, and start
> it again, and usually, it would be fine idling normally at
> 800-1000... for
> weeks.
>
> Then came the highway scenarios... driving at full throttle
> (yes, in Europe
> we are allowed to drive fast) If I would take my foot off
> the gas to down
> shift, the engine speed would only go back down to like
> 3000 RPM and sit
> there.. on the highway this was not so much of a problem.
>
> Then it started doing this in the city.... and it was not
> much fun. Every
> traffic light, sitting there with my Vanagon idling at 3000
> RPM. Turning it
> off, and then starting it again... only to have it surge up
> again within a
> few seconds.
>
> Then it started dying on me... my only guess was that it
> was now getting
> flooded by this high idle, and I could not start it for 20
> minutes or so
> afterwards.. it would just crank... no spark... or drownded
> spark... or
> something.
>
> In order to get home from a grape harvest last fall, I
> disconnected the Idle
> Stabilizer Valve.. and drove a few hundred miles this way..
> but it still was
> not happy. I stopped for gas, and it would not start up...
> until 30 minutes
> went by.
>
> Long story short. Now it will surge right up to 3000 RPM
> within seconds of
> starting.. and if I am in a city driving situation, this
> means overheating
> and constant key turning... not fun.
>
> I have now gone through the components which I think can be
> causing this,
> and have replaced the Idle Stabilizer Valve, the Idle
> Stabilizer Control
> Unit, the Air Flow Sensor and am ready now to get this
> crazy modified wiring
> harness.
>
> My question... is this wire an important component, should
> I buy it, was it
> determined by VW that the original harness was in fact
> defective (if so,
> shouldn't they be passing these $100 wires away for free)
> ... and that is
> why this part even exists?
>
> Also... is there any way to get this part for less than 100 bucks?
>
> And lastly... is there any other componant that I should be
> looking at,
> besides perhaps the throttle switch, which would be
> responsible for pushing
> the idle all over the place like this (Please do not
> suggest a new ECU... I
> just replaced one in my golf and it cost a fortune!)
>
> Thanks for any insights you all can provide!
>
> RSF
>
> PS... while testing the idle, I had the Vanagon running in
> my driveway at
> idle... and I would then disconnect the idle stabilizor
> valve... and it
> would go back down to a pleasant, normal idle. As soon
> as I attached it
> again... it rose to 2500. I have two of these little
> creatures now, and
> both hum and sound like they are actually working... I have two of
> everything... air flow sensor, and idle stabilizor control
> unit... good
> thing that eBay is around or I would be bankrupt by now!
>
>
> <º)))>{ <º)))>{ <º)))>{ <º)))>{ <º)))>{ <º)))>{
>
> Robert S. Fish
> Salzburg, Austria
> 1987 Wolfsburg Vanagon 2.1 Weekender
> 1987 Golf Cabriolet
> 1991 Golf
>
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