Date: Mon, 21 Mar 2016 16:33:25 -0700
Reply-To: vw_van_fan_Mark <madvws@COX.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: vw_van_fan_Mark <madvws@COX.NET>
Subject: Re: Vanagon syndrome...it sucks!
In-Reply-To: <56F0767B.6010707@turbovans.com>
Content-Type: text/plain; charset=windows-1252; format=flowed
I have seen many of them fail in 2.1 Vanagons. I didn't suggest to
replace it right off the bat. Test first by simply unplugging the
connector to it and seeing what effect it has or doesn't have on the
specific problem at hand. The van can many times run fine without the
switch connected at all, though it is good to have it there and working
for various reasons. The issue is how nearly impossible it can be to
drive with one that is acting up in certain ways. If the van drives just
as badly with it unhooked then look elsewhere for the problem.
The TPS throttle position switch has several failure modes. Sometimes it
is just wear on the external cam and the switch is fine. In this case
adjustment may help, or replacement of the cam piece. But that failure
mode isn't what usually causes the severe jerking. Sometimes the switch
itself begins to stick closed internally and that is the failure that
makes it most difficult to drive. For that failure replacement of the
switch is usually called for. So for the current symptoms if the switch
is indicated as the problem then I would plan to replace it.
Mark
SDF ( aka ;jim lahey' - Scott ) wrote:
> given that that is an adjustable micro-switch ..
> just replacing it does not seem like a good idea right off the back.
>
> I've never seen one fail, just fail to be moved properly by the little
> lobe on the underside of the Throttle body.
> of course...since no mechanicals are involved like worn TB shaft
> bushings ..
> the electro-pneumatic idle switch seems like the way to go ..
> it reads the actual air, not a mechanical position of something that
> 'should' be related directly to air , but after 25 + years that's often
> not the case I would think.
>
> I have about 5 TB's to play with ..some return to zero position easier
> than other ones.
> There are rebuilt ones available ..should that be related to this
> strange issue on this van.
>
> lots of vans are running with non-working or not-adjusted-right throttle
> switches and they don't have intermittant loss of power.
> of course it's really nice to have things pretty right and very well in
> tune.
>
> scott
>
> On 3/20/2016 4:39 PM, vw_van_fan_Mark wrote:
>> Before doing anything that costs much money or much time, unplug the
>> throttle position switch connector. If it doesn't help, nothing lost. If
>> it cures it, order a new switch.
>>
>> Mark
>>
>> Jason Ellis wrote:
>>> Ok all, I've searched The Samba and tons of other websites for my
>>> issue. Maybe one of the gurus here can help.
>>>
>>> I have typical vanagon syndrome symptoms. Driving on highway for a
>>> while, then suddenly loss of power and bucking. Turn off engine,
>>> restart and all is good for an indeterminate amount of time. I did
>>> notice that just before (10 sec or so) the power loss starts, I seem
>>> to have a smoother running engine with a hair more power. I also had
>>> the syndrome start and I exited the freeway with very little power. I
>>> shifted into 3rd and it chugged a couple of times and the BAM, like a
>>> switch was turned on, the van power came back. Drove home another 30
>>> min on highway with no problem.
>>>
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