Date:         Thu, 19 Aug 2010 13:19:17 -0700
Reply-To:     Tom Young <tomyoung1@COMCAST.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Tom Young <tomyoung1@COMCAST.NET>
Subject:      Re: Heat, vapor lock, won't start?
In-Reply-To:  <alpine.BSF.2.00.1008182335280.37813@bemnet.pair.com>
Content-Type: text/plain; format=flowed; charset="iso-8859-1";
              reply-type=response

Vapor lock in a fuel injected engine is a rare occurrence because the fuel
is under pressure for the entire fuel loop.

There's another issue that occurs to engines with AFMs that also results in
the problem you describe, and that's the progressive weakening of the spring
inside the AFM over time, leading to a chronic "too rich" situation at all
speeds.  Although this can sometimes be corrected by adjustment of the
mixture screw on the AFM, I've experienced the situation where the spring
weakens to the point that fuel/air can't be adjusted back to a proper
mixture with
the screw alone.

When the engine is cold in the morning and during cooler weather the "too
rich" situation frequently isn't that noticeable, and that's why you might
not experience this problem in Seattle.  But, let it get hot enough, like in
Idaho, and re-starts can become impossible due to what essentially is a
flooding situation.  The engine can even die while running because it's
getting too much fuel. You have to wait 20 minutes or so to let the excess
fuel in the air distribution box evaporate and let the engine cool down
before the engine can be started up again.

One trick to getting going that sometimes works here is to start up the
engine with the accelerator pedal all the way to the floor, allowing as much
air as possible into the engine, which allows the "excess" fuel to be
burned.

Tom Young



----- Original Message -----
From: "A. Hurley" <ahurley@SHOPVIEWIT.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, August 18, 2010 8:38 PM
Subject: Heat, vapor lock, won't start?


> Hi,
>
> This problem seems to happen only when we go to Idaho in summer - each
> year I go through the temperature sensor, fuel filter, etc - in a panic
> and the van works fine in Seattle.
>
> It's a bit of a joke that it takes three times to start on a hot day - but
> it's not a joke when you can't get it to start at all.
>
> Today I went through the air filter, fuel filter, checked all the lines,
> and then found something online about a recall due to vapor lock.
>
> One mechanic told me to install a second fuel filter.
>
> We have taken off the gas cap.
>
> It starts fine in the morning and after twenty minutes at rest.
>
> It dies in odd places that could be dangerous.
>
> Is it the gas tank?
>
> Thanks,
>
> Andree
>


----- Original Message -----
From: "A. Hurley" <ahurley@SHOPVIEWIT.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Wednesday, August 18, 2010 8:38 PM
Subject: Heat, vapor lock, won't start?


> Hi,
>
> This problem seems to happen only when we go to Idaho in summer - each
> year I go through the temperature sensor, fuel filter, etc - in a panic
> and the van works fine in Seattle.
>
> It's a bit of a joke that it takes three times to start on a hot day - but
> it's not a joke when you can't get it to start at all.
>
> Today I went through the air filter, fuel filter, checked all the lines,
> and then found something online about a recall due to vapor lock.
>
> One mechanic told me to install a second fuel filter.
>
> We have taken off the gas cap.
>
> It starts fine in the morning and after twenty minutes at rest.
>
> It dies in odd places that could be dangerous.
>
> Is it the gas tank?
>
> Thanks,
>
> Andree
>