Date: Wed, 29 Aug 2012 22:25:43 -0400
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: Auxiliary Air Regulator - Testing - Digijet
In-Reply-To: <65B36522-AD95-4A69-9D6B-C09423EFECCC@comcast.net>
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Don't apologize. I am not a teacher or even a good writer so I sometimes am
not clear. I don't play one on radio or TV either.
The auxiliary air regulator works just like an electric choke on a
carburetor. Remember when cars had those things?
Anyway, when the engine is started cold the AAR is open some amount based on
ambient temperature. All it does is bypass the throttle plate to allow more
air and thus an increased idle speed. The 12 volt heater causes the valve to
close. The inside of the engine will heat up very quickly, much faster than
the engine case or even the coolant so the heater helps to close the valve
and return the idle to normal quickly. Now after the engine case is warm,
when the engine is turned off the warm engine keeps the vlave closed so that
when restarted the idle will be normal. The valve not open until things get
cold and a fast idle is needed again.
Dennis
-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
George Laubach
Sent: Wednesday, August 29, 2012 9:55 PM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Auxiliary Air Regulator - Testing - Digijet
Thanks Dennis. So the engine temp directly heats the aar metal housing and
the gate "mechanically" is open (cold), then closes "mechanically" as the
engine warms? If so (and apologies for my ignorance in advance), what does
the 12 volts do?
Sent from my iPad
On Aug 29, 2012, at 8:24 PM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> The AAR gets 12 volts anytime the engine is running. It operates both on
engine temperature and the heater speeds up the process from a cold start.
It operation is very slow so it is not the cause of any erratic operation.
Do make sure the wiring is not swapped with the throttle position switch if
it uses the same connector. If swapped the switch is now toast and with the
AAR connected to the switch connector the ECU will always think the throttle
is closed.
>
> Dennis
>
>
> -----Original Message-----
> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Skip
> Sent: Wednesday, August 29, 2012 9:05 PM
> To: vanagon@GERRY.VANAGON.COM
> Subject: Auxiliary Air Regulator - Testing - Digijet
>
> '84 Westy, Digijet, 1.9L case with a 2.2L GoWesty kit
>
> I've often suspected a less than ideally working AAR. My cold idle is
sometimes wonderful, sometimes choppy, sometimes "wandering" (up and down).
>
> It's so darn hard to reach the AAR connector without taking out half the
right side of the engine ancillaries.
>
> So I have a used spare on the bench, as well as a charged spare battery.
>
> Question: How can I test the open/close mechanism of the spare AAR? Can
I simply power it by connecting leads from the battery to the "Heating coil
terminals" on the AAR? And when I charge it, should the "gate" close or
open?
>
> Please advise and thanks!
>
> Once I have the answer I'll dig into the one on the engine and check the
installed AAR. Bentley 24.28 provides cryptic instructions (and I need to
wait for the engine to cool to "pinch the hose"). Regarding 24.28, what is
the voltage measurement that I should see when I check the connector, and
("with the engine running") should the engine be warm or cold when I measure
voltage?
>
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