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Subject:Re: Isolating an idle problem?
From:Dennis Jowell
Date:Mon, 22 Dec 2014 06:49:33 -0500

So does mine, back roads in Vermont are super dusty.

Dennis Jowell
Scotch Hollow Farm
West Newbury, Vermont 

> On Dec 21, 2014, at 10:15 PM, Don Hanson <dhanson928@GMAIL.COM> wrote:
> 
> All good suggestions, thanks.  The engine in my van isn't sealed off.  The
> whole motor gets  covered with dust during prolonged back road travel.
>> On Dec 21, 2014 6:43 PM, "Dennis Haynes" <d23haynes57@hotmail.com> wrote:
>> 
>> Why should the idle valve see any substantial amount of dust? That is what
>> the air filter is for. If the idle valve is seeing dust I hate to think
>> what the engine is ingesting. Same for any oily deposits or good. Oil in
>> the intake track is a sign of excessive piston blow-by or a crankcase
>> venting problem.
>> 
>> As for the idle going down to 400 rpm don't bother looking at the idle
>> valve first. The engine warmed up should never go that low even with the
>> valve fully closed. Get the book and get the basic settings correct. If you
>> can't use current or duty cycle to set the base idle speed set the idle to
>> about 750-800 rpm (engine warm, all consumers off) with the valve unplugged
>> or blocked off. This will get you close.
>> 
>> Since it is intermittent you need to look at fuel delivery or mixture
>> control. I would take a look at the O2 sensor particularly after changing
>> the design (eliminating the heater). Either too rich or too lean can create
>> idle problems. Another possibility is a cylinder miss-fire. Again fuel
>> delivery-cylinder balance should be checked.
>> 
>> Dennis
>> 
>> 
>> -----Original Message-----
>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf
>> Of Don Hanson
>> Sent: Sunday, December 21, 2014 9:25 PM
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: Re: Isolating an idle problem?
>> 
>> I'll try cleaning the idle control module as per a link posted.  I've
>> never cleaned this one and in my installation it sees lots of dust.
>>> On Dec 21, 2014 12:46 PM, "Stuart MacMillan" <stuartmacm@gmail.com> wrote:
>>> 
>>> Best I can do: http://www.gowesty.com/ec_view_details.php?id=23468 <
>>> http://www.gowesty.com/ec_view_details.php?id=23468&category_id=&categ
>>> ory_parent_id> &category_id=&category_parent_id=  don’t expect to get
>>> your core charge back either, but you might get lucky.  I found a used
>>> one locally for $75 from Vanagon repair shop.
>>> 
>>> 
>>> 
>>> Stuart
>>> 
>>> 
>>> 
>>> From: Jim Felder [mailto:jim.felder@gmail.com]
>>> Sent: Sunday, December 21, 2014 11:36 AM
>>> To: Stuart MacMillan
>>> Cc: Vanagon mailing list
>>> Subject: Re: Isolating an idle problem?
>>> 
>>> 
>>> 
>>> Somebody give me a part number, I'm pretty sure I have a loaner that
>>> could be purchased if needed and returned if not.
>>> 
>>> 
>>> 
>>> Jim
>>> 
>>> 
>>> 
>>> On Sun, Dec 21, 2014 at 1:33 PM, Stuart MacMillan
>>> <stuartmacm@gmail.com>
>>> wrote:
>>> 
>>> Idle control module, or a vacuum leak (hook up a vacuum gauge).  Try
>>> to find an ICM to borrow for testing, they are expensive. It's mounted
>>> way behind the right tail light. Not a very good location for a
>>> computer that is not waterproofed.
>>> 
>>> Stuart
>>> 
>>> 
>>> -----Original Message-----
>>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On
>>> Behalf Of Don Hanson
>>> Sent: Sunday, December 21, 2014 8:43 AM
>>> To: vanagon@GERRY.VANAGON.COM
>>> Subject: Isolating an idle problem?
>>> 
>>> I've been seeing an intermittent low idle-sometime no idle with my
>>> Digifant
>>> 84 van 92 rabbit/fox/Jetta ecu, etc.  This condition is occasional,
>>> when not happening, the engine behaves normally, my fuel consumption
>>> has not changed.
>>>  My normal idle is about 900 rpm.  Recently I have had the idle
>>> decide to run at around 400 rpm...it seems to be smooth, but 400 rpm
>>> is too low and now the motor sometimes dies down there.  When I cycle
>>> the key and re start, it will again run at the low idle...no
>>> "reset"... I have a new temp II sensor and new plugs...the old plugs
>>> read normal.  My idle control thingy hums as normal and I have no
>>> obvious new vacuum leaks. Multiple different fuel sources.  Throttle
>>> switch seems to conform to the Bentley, though I have so far only
>>> check ed the mechanical, I have not run any electronic diagnosis yet.
>>>  Anyone want to suggest the most likely cause to this sometimes dying
>>> of my Digifant inline? Tia, Don Hanson
>>> 
>>