Date:         Wed, 17 Jul 2024 07:57:43 -0700
Reply-To:     mark@MARKMCCULLEY.COM
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Mark McCulley <mark@MARKMCCULLEY.COM>
Subject:      Re: Possible Vanagon Syndrome...
Content-Type: text/plain; charset=utf-8

The switch is located on the throttle body. Its purpose is to signal the ECU of two conditions: throttle closed and throttle wide open. The usual problem is a switch that is out of adjustment and doesn’t close when you take your foot off the gas. The fix is to adjust the switch position. In my case the switch was bad and was always closed. To repair, I purchased a new switch from GoWesty. This is for manual transmission, not sure if it is the same for automatics but I expect it is.

You should be able to hear the switch click when the motor is off and you manually open the throttle a bit in the engine compartment. A better test is to remove the wiring harness connector to the switch and use an ohmeter to verify that the switch is working correctly. It should be closed (zero or very low resistance) when throttle closed or wide open, open (infinite resistance) when the throttle is open a bit. 

It can get more nuanced than this but this is the basics. 

-Mark

> On Jul 16, 2024, at 9:54 AM, Eric Caron <ericcaron96@comcast.net> wrote:
> 
> Hi Mark,
> 
>   Can you share a bit more?  Did you replace the switch or clean it?  Where is it located?  
> 
> Somewhere in the tips is the  solution to our list’s current puzzle and  we all gain useful info.
> 
> ERic Caron
> 
> 
> 
> 
>> On Jul 15, 2024, at 4:14 PM, Mark McCulley <mark@MARKMCCULLEY.COM> wrote:
>> 
>> I had similar symptoms about a year ago, turned out to be a bad throttle position switch.
>> 
>> -Mark
>> 
>>>> On Jul 15, 2024, at 10:56 AM, Richard Koerner <rjkinpb@sbcglobal.net> wrote:
>>> 
>>>  Oh, Syncro....plastic tank way in the back...but I imagine they too might have some kind of screen on outlet which might get clogged with accumulated debris.  But I know nothing of Syncro fuel system.  Other than it's a real bear to remove that tank!
>>> 
>>>> On Monday, July 15, 2024 at 10:48:50 AM PDT, Markus Benne <mbenne@m-bass.com> wrote:  
>>> 
>>> Thanks for that.  Tank was freshly cleaned over the winter.   It was very, very hot out.   And a fresh tank of gas started the day.
>>> Forgot to mention it's a syncro, but your point is still valid.  
>>> 
>>> |   From: rjkinpb@sbcglobal.netSent: July 15, 2024 1:43 p.m.To: vanagon@gerry.vanagon.com; mbenne@m-bass.comSubject: Re: Possible Vanagon Syndrome... |
>>> 
>>> 
>>> How old is your fuel tank?  Clogged fuel tank outlet will start causing these issues.  Was it a hot day?  High ambient temperatures makes it easy for Fuel Pump to cavitate; these bubbles in liquid fuel cause loss of power and even dying.  Next day after fuel is cold again, the problem disappears.  But then you drive again on hot day, and problem reappears as gasoline in tank warms up to ambient.  Since fuel tank is downwind of radiator, all that hot air flowing by helps also to heat up gasoline.  If clogged outlet from old tank, there is no fix; you've got to replace Fuel Tank.
>>> 
>>> 
>