Date: Thu, 6 Mar 2008 09:12:08 -0500
Reply-To: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject: Re: 2.1 Electronic Idle Control valve
Content-Type: text/plain; format=flowed
You would naver want an idle speed of 1,500 rpm. In fact at closed throttle
that should put into fuel cut off. The ECU does not get any feedback for AC,
power steering, or anything from the idle speed controller. The idle speed
controller also does not see the throttle switches. The ICU Is there to
stabilize the idle to compensate for load changes and constant mixture
variations due to the O2 sensor. The inputs the ICE receive are engine
speed, engine temperature shared with the temp 2 sensor for the ECU and
feedback for AC and power steering. For some reason there is no feed back
for auto tranny not being in neutral. The actual jump in idle speed should
only be 100 rpm or so but except for directly after a cold start, never over
1,000 rpm. Imagine an automatic idling in reverse at 1,500 rpm! Remember
run away Audis?
The idle control valve is normally closed. When the idle speed goes below
the set point, the ICU sends pulses to the valve to open it. The duration
(duty cycle) determiens how much it opens bypassing the throttle to give
more idle speed. If the engine has another problem causes a weak or erratic
idle then it will not be able to compensate for the added load of AC or
power steering and you will get stalling. A defective AC system can also be
a problem.
Dennis
>From: John Rodgers <inua@CHARTER.NET>
>Reply-To: John Rodgers <inua@CHARTER.NET>
>To: vanagon@GERRY.VANAGON.COM
>Subject: Re: 2.1 Electronic Idle Control valve
>Date: Wed, 5 Mar 2008 01:26:31 -0600
>
>Doesn't the Stabilizer control come into play when the AC is on, as in
>providing a signal to the ECU to kick up the idle speed to 1500 of so
>when the AC is on.and the throttle is set for idle as in at a stoplight
>or something.?
>Without it there is difficulty in keeping the engine idling when the AC
>is on. Engine will stall under the load of the AC.
>
>John Rodgers
>88 GL Driver
>
>Scott Daniel - Shazam wrote:
>>Electronic Idle control valves operate with a 'duty cycle' I believe.
>>
>>It's most definitely not 'on or off' .
>>
>>And I don't like that the Control Unit for it is a 500 dollar part of some
>>excessive number ( $ 384.00 list ? )
>>
>>They'll work fine with the idle valve unplugged of course - just won't
>>have
>>fast idle cold.
>>
>>I haven't had time to try it, but I wonder how a good old fashioned
>>Auxiliary Air Valve from a 1.9 would work, to provide faster idle when
>>cold.
>>
>>
>>Scott
>>
>>
>>
>>-----Original Message-----
>>From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
>>John Bange
>>Sent: Tuesday, March 04, 2008 10:11 PM
>>To: vanagon@GERRY.VANAGON.COM
>>Subject: Re: Calling John Bange
>>
>>
>>
>>
>>
>>
>>>Have you gone any further in the development of some alternative to the
>>>
>>
>>
>>>Idle Stabilizer Control for the vans.
>>>
>>
>>
>>
>>
>>>Just curious. I have control issues.
>>>
>>
>>
>>
>>
>>
>>Unfortunately, that project is kinda stalled on the idle valve control
>>
>>scheme. Not having any test equipment more complicated than a $40 Fluke
>>
>>multimeter, I can't figure out how to make the air valve open and close.
>>
>>IAll I know is that it's not as simple as "0v=closed, 12v=full open".
>>Anyone
>>
>>out there know what the idle controller does with that valve?
>>
>>
>>
>>--
>>
>>John Bange
>>
>>'90 Vanagon - "Geldsauger"
>>
>>
>>
>>
>>
>>
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