Date:         Fri, 8 Aug 1997 17:10:39 -0700 (PDT)
Sender:       Vanagon Mailing List <vanagon@vanagon.com>
From:         Tom Young <young@sherlock.sims.berkeley.edu>
Subject:      Re: Computer Problem?

On Fri, 8 Aug 1997, Erik Rhodes wrote:

> 	In my '79 westphalia, I've got some kind of fuel injection
> problem that has been befuddling me for a great while.  It starts up
> fine but as soon as it warms up and the cold start valve starts turning
> off, it gets way weak and sometimes even dies if I don't up the RPM.

The cold start valve is powered only when the starter is turning over the 
engine.  Once you switch from "Start" to "Run" the cold start valve is no 
longer in the game.  However, the auxiliary air regulator starts out wide 
open with a cold engine and slowly closes as the engine warms.

> When it finally gets warmed up and driving, it's fine, runs like the
> happy beast it is while it's temperature is in the medium range.  But
> within twenty minutes of driving--I'm guessing when the temperature has
> reached full operating temp--I stop at a stop light and the RPM is too
> high, probably around 1300-1600RMP, though I haven't tested it yet.
> 
> 	I've replaced the temp head sensor and fixed a weak ground
> connection and now just finally got a spiffy new Bosch air flow meter
> (aye, this cost a pretty penny, but I needed it for smog check anyway)
> and each thing has actually improved the driving in other ways--lots
> more power now--but I still have this problem.
> 
> 	I can't think of anything left it could be except the control
> unit, ye old computer itself.  Visual inspection shows hoses and such
> are fine, no cracks or nuthin.  Has anyone ever seen anything like this?

It *could* be a vacuum leak; visual inspection just isn't enough 
sometimes to find every leak, particularly if the leak is on the bottom 
of the hose.  (The hose running from the decel valve to the large 
intake hose on my bus had such a leak, although the hose looked fine.)  
I'd first do a thorough inspection for leaks.  Might also test the #1 
temp sensor, though you'd hope with a new air flow meter this wouldn't be 
a problem.

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Tom Young                young@sherlock.SIMS.Berkeley.EDU
Lafayette, CA  94549     '81 Vanagon
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