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
>