Date:         Wed, 27 Nov 1996 22:25:03 -0700
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         "Will Wood" <wkwood@burgoyne.com>
Subject:      Re: 91 runs rough cold



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> From: Eric Baden <ebaden@warren-wilson.edu>
> To: Multiple recipients of list <vanagon@lenti.med.umn.edu>
> Subject: 91 runs rough cold
> Date: Wednesday, November 27, 1996 5:09 PM
> 
> Greetings - 
>   A friend called this evening from Connecticut re: his 91 vanagon 
> running very rough while it's cold. It starts right up and then for the 
> next fifteen minutes or so  - before it reaches operating temp. - it runs

> really rough - accelerating with no load, or while driving it surges. He 
> describes it as if it's running rich - but there's no black smoke. The 
> problem is getting worse and the ambient temperature is in the 30's. He's

> read the resistance of the temp sensor and says it correct at cold temp. 
> It seems to run normally when fully warmed up. Any ideas as to what might
be 
> causing this?
>   Perhaps related - he wonders about the procedure for timing it with a 
> timing light -  (Apparently the book listed procedure for the digifant 
> engine is not very clear or doesn't involve a light).
>                 Thanks in advance.
>                       Eric
>   
Sounds like the EMU isn't getting the proper signal from the temperature
sensor(s).  There's a sensor for the intake temperature and the water
temperature that tell the EMU to activate the cold start valve (5th
injector).  This is activated when the engine is cold and supplies the
requisite extra fuel to feed the motor until it warms up.