Date:         Tue, 1 Oct 2013 19:08:59 -0400
Reply-To:     Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject:      Re: poor startup and cold running  2.1 WBX
Comments: To: "greentabe-vanagon@yahoo.com" <greentabe-vanagon@YAHOO.COM>
In-Reply-To:  <1380606754.90033.YahooMailNeo@web171901.mail.ir2.yahoo.com>
Content-Type: text/plain; charset="iso-8859-1"

Once the temp 2 sensor is proven out (including wiring) and the air flow
meter is good, poor starting and running performance is usually a sign of a
mechanical or fuel delivery problem. Bad sealing intake valves and worn
guides can make for some real fun. So begin with the compression and leak
down tests. Then the next step is checking the injectors. Bad spray patterns
usually show up as poor cold running problems Once things get warm and the
fuel can vaporize with heat the engine will be more forgiving. Excessive
carbon on the back of the intake valves will also cause cold running issues
as the fuel is being absorbed instead of vaporized. 

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
greentabe-vanagon@yahoo.com
Sent: Tuesday, October 1, 2013 1:53 AM
To: vanagon@GERRY.VANAGON.COM
Subject: poor startup and cold running 2.1 WBX

Hi all,

I could probably figure this out on my own but it's more fun to have a
conversation about it:  Our '90 MV will not start when cold unless I crank
the engine over briefly (less than a second), turn the key off, crank it
over briefly, turn the key off, and so on for maybe ten cycles .  Then it
will fire and if I keep cranking it will eventually start.  I theorize that
the ECU gives an extra shot of gas every time you cycle the power amd it
needs this extra fuel to run.

Once it is running, it idles really smoothly.  If I open the throttle all
the way the engine will misfire before speeding up.  Once the engine is warm
this behaviour improves but is still present.  Also, if it is running at
speed and I close the throttle suddenly, the engine runs until it reaches
idle speed, then cuts out and stalls..


I have checked the temperature sensor and idle switch already.  The idle
system and idle air bypass seem to be working.  I remember checking the
timing a while ago but I haven't done it lately.  From inspection I don't
believe I have any vacuum leaks but I haven't checked super carefully yet.

Any ideas?

tabe_johnson/90MV