Date:         Mon, 27 Aug 2012 03:26:31 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Re: Poor Hot Start Discovery - midway through solution
Comments: To: neil n <musomuso@gmail.com>
In-Reply-To:  <CAB2RwfhkG_ZWpwNnebZ5ECJ7neD0YQ43YPm6818CFcAmhqfioA@mail.g
              mail.com>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 11:09 PM 8/26/2012, neil n wrote:
>And I don't know if the OP is running a 2.1 or 1.9 but on the 1.2
>the big hose from purge valve goes downstream of the AFM into the
>"T" at intake manifold. This is the hose I was referring to.

I was even more mixed up than I thought.  Referring to 20.33 - fuel
vapors come from the tank and pass freely into the charcoal canister
where they are in theory adsorbed onto the surface of the activated
charcoal therein.  Air, and any vapor that is not adsorbed, passes
out of the bottom of the canister into the airbox, between filter and AFM.

When the engine runs and the throttle is opened slightly, a vacuum
port in the throttle body is uncovered and sucks (through a tiny
orifice) on the activating line of the vacuum-operated purging
valve.  This opens the valve, allowing manifold pressure to act
(through a somewhat larger orifice) on the canister, pulling filtered
air slowly up through it from inside the airbox and carrying along
such molecules of gasoline as detach themselves from the activated charcoal.

Bentley is opaque on whether the 2.1l setup has a restricting orifice
on the canister suction line or whether it's only the 1.9l, where
it's built into an angled tee in the hose passing from the intake
manifold to the auxiliary air regulator.  I suspect it does, however,
because since this isn't passing through the AFM it is in effect a
vacuum leak, so they'd want to keep it small.

Sorry for the mixup.  I still don't think it's going to have any
practical effect on starting.

Yours,
d