Date: Wed, 29 Aug 2012 21:42:00 -0500
Reply-To: George Laubach <skiplaubach@COMCAST.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: George Laubach <skiplaubach@COMCAST.NET>
Subject: Re: Auxiliary Air Regulator - Testing - Digijet
In-Reply-To: <BAY152-ds19FBAAC3F64886A26AA0BBA0A70@phx.gbl>
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All right. Very clear. Thank you a well understood explanation.
Skip
Sent from my iPad
On Aug 29, 2012, at 9:25 PM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> 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?
>>
>