Here's how I like to operate the cold start valve on any old system like
this one...
-  by manual push button.  ( they operate o 12 volts )
Makes it into a 'primer' button...
turn on the key, hold the button in say .....2 seconds, hit the starter ..
catch it to fire up, taping the button a few times  now and then for the
first 20 seconds of running.

works just great !
Got that working on a Mercedes 450SLC ( for sale too, cheap ) , wired to the
washer button.
And thank goodness waterboxers don't have cold start valves.

Scott

----- Original Message -----
From: "Zoltan" <thewestyman@GMAIL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Monday, May 03, 2010 11:53 PM
Subject: Re: Starts day, won't at night ...

> So, this means, that the Thermo time switch measures ambient temp. and
> activates accordingly.  Is that right?  I have tried to measure voltage
> and
> see if the test light comes up when cranking, as the Bentley says.  I
> guess,
> there should be some voltage that would activate a little light bulb in my
> tester, and would dim after a few seconds.
> Is there any other way to test the TTS?  Maybe with Ohm meter?  Or
> continuity tester?
> Zoltan
>
> ----- Original Message -----
> From: "Old Volks Home" <oldvolkshome@GMAIL.COM>
> To: <vanagon@GERRY.VANAGON.COM>
> Sent: Monday, May 03, 2010 10:18 PM
> Subject: Re: Starts day, won't at night ...
>
>
>> To elaborate on Dennis' comment, sounds like the Thermotime Switch has
>> gone
>> bad.  In cold weather (nights, mornings) under a certain ambient
>> temperature
>> (Bentley shows this and how to test one), it activates the cold start
>> valve
>> during the start cycle to richen the mixture.  The cold start valve is
>> told
>> to shut off by the ECU when the engine fires up.
>>
>> Temp I or II have nothing to do with the Cold Start circuit.
>> --
>> Jim Thompson
>> 84 GL 1.9 "Gloria"
>> 84 Westfalia 2.1 "Ole Putt"
>> 72 411 Station Wagon "Pug"
>> 75 914 1.8 (No Name Yet)
>> Full Timing Since March 1999
>> oldvolkshome@gmail.com
>> http://www.oldvolkshome.com
>> ***********************************
>> On Mon, May 3, 2010 at 9:56 PM, Dennis Haynes
>> <d23haynes57@hotmail.com>wrote:
>>
>>> The air cooled engines have separate cold start injector which is
>>> controlled
>>> by the thermo-time switch.
>>>
>>> Dennis
>>>
>>> -----Original Message-----
>>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
>>> Of
>>> Zoltan
>>> Sent: Friday, April 30, 2010 6:07 PM
>>> To: vanagon@GERRY.VANAGON.COM
>>> Subject: Starts day, won't at night ...
>>>
>>> As the headline says.  This is a 1982 air-cooled van.  Daytime, when
>>> it's
>>> a
>>> little warmer, it starts right away.  But somehow at night or early
>>> morning,
>>> when it's a little colder, it won't.
>>> I know, there are two temp. sensors and usually the temp. II sensor is
>>> the
>>> one I would change.  I just haven't experienced this kind of behavior.
>>> Maybe none of you would know and send me a message about it, and I will
>>> go
>>> out and buy a Temp. II sensor and see if it works.  But what if the
>>> Temp.
>>> I
>>> (one) sensor is the one that is not working as it should?  I never heard
>>> of
>>> that to be changed.
>>> My respects to the List.
>>> Zoltan
>>>