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?
>> 
>