Date:         Sun, 12 Aug 2001 19:24:38 -0700
Reply-To:     "Andrew G. Martin" <agmartin@GIS.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         "Andrew G. Martin" <agmartin@GIS.NET>
Subject:      Re: 1991 2.1 l auto Vanagon stall on warm-up
Content-Type: text/plain; charset="iso-8859-1"

My brother had similar problem with his '91 Carat.  It went on and off for
many months.  After testing and re-testing everything fuel and electrical
related he almost gave up.  One day he noticed the dreaded sweet smell of
engine coolant under the back seat.

A close inspection of rear heater core revealed a hairline crack in the
plastic control valve attached to the heater core.
After looking at the Bentley Manual diagrams of the cooling system, he
decided that this newly discovered problem was somehow related to the
existing Start/Run/Stall/Start/Run Rough/Stall/Start/Run Fine mystery.

THE AIR BUBBLE THEORY
His theory was that air was getting into the cooling system through the
cracked heater core valve and forming an air bubble overnight.  After
starting the cold van in the morning and driving for a few blocks the air
bubble would move out of the heater core, pass through the distribution unit
and head directly to the thermostat housing AND the Temp Sensor for the fuel
injection system/computer. Engine stalls.  Shut key off, computer resets
itself (?) turn key on, engine starts again and stalls again.  At this point
he would wait a few minutes before trying to start the engine again.  Turn
the key on, engine starts and runs great all day.  Next day same symptoms.

TO FIX
He replaced the heater core valve, bled all the air out the cooling system
(following Bentley Manual instructions)and the van has run fine ever since.

I know what some of you are thinking...

I asked him about the possibility of the two conditions NOT being related in
any way.  I said, "WHAT IF, while performing the heater core valve repair
and coolant bleeding process, he had somehow inadvertently done something
that corrected the Start/Stall problem????"  Hmmmm.  Bumped a loose wire,
tightened a grounding post, disconnected something, whatever.  He assured me
that was not the case and insisted he had been mindful of that scenario
while performing the repairs.

He is a highly trained and skilled Mechanical Engineer with a huge diagnosis
background.  I believe him.

Andrew

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On Behalf
Of bnimmo
Sent: Saturday, August 11, 2001 8:42 PM
To: vanagon@GERRY.VANAGON.COM
Subject: 1991 2.1 l auto vanagon stall on warm-up


1991 2.1 l auto vanagon:

From cold - starts fine, runs for about three blocks, then starts to run
rough,
eventually stalls. Starts immediately, and runs fine for another block, then
repeats the stall. Does this about 3-4 times, then runs fine for the rest of
the
day.

Any suggestions?

Thank you, Brodie Nimmo