Date:         Wed, 4 Jan 2017 05:14:02 +0000
Reply-To:     Dennis Haynes <d23haynes57@HOTMAIL.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Dennis Haynes <d23haynes57@HOTMAIL.COM>
Subject:      Re: PS Pump switch high idle question
Comments: To: Alistair Bell <albell@shaw.ca>
In-Reply-To:  <3D799583-528E-41B5-BE63-E8C11F854CB4@shaw.ca>
Content-Type: text/plain; charset="us-ascii"

That air through the valve is metered by the air flow meter. Has the same effect as opening the throttle. 

Dennis


-----Original Message-----
From: Alistair Bell [mailto:albell@shaw.ca] 
Sent: Wednesday, January 4, 2017 12:12 AM
To: Dennis Haynes <d23haynes57@hotmail.com>
Cc: vanagon@GERRY.VANAGON.COM
Subject: Re: PS Pump switch high idle question

Ok got it. With the effect of allowing more un metered air into the plenum.

Thanks

Alistair



> On Jan 3, 2017, at 8:41 PM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
> 
> The increase in duty cycle effectively opens the valve further. 
> 
> Dennis
> 
> 
> 
> -----Original Message-----
> From: Alistair Bell [mailto:albell@shaw.ca] 
> Sent: Tuesday, January 3, 2017 10:51 PM
> To: Dennis Haynes <d23haynes57@hotmail.com>
> Cc: vanagon@GERRY.VANAGON.COM
> Subject: Re: PS Pump switch high idle question
> 
> So it's as I guessed, the pulse cycle is biased towards more ICV valve open time when PS switch closes. But hold on, I misread, your saying the pulse bias opens the ICV further and not a bias towards on time?
> 
> Thanks Dennis
> 
> Alistair
> 
>> On Jan 3, 2017, at 7:43 PM, Dennis Haynes <d23haynes57@hotmail.com> wrote:
>> 
>> The PS pressure switch is an input to the idle valve controller. There is also an input for the AC compressor clutch. The idle controller looks at engine speed, temperature, and those other inputs and then modulates the valve to get to the desired speed. The modulation is based on providing a pulsed current to the valve coil. The duty cycle is increased to open the valve further.  
>> 
>> Dennis
>> 
>> -----Original Message-----
>> From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of Alistair Bell
>> Sent: Tuesday, January 3, 2017 10:03 PM
>> To: vanagon@GERRY.VANAGON.COM
>> Subject: PS Pump switch high idle question
>> 
>> Hi,
>> 
>> Can someone school me on the way the PS pump switch affects the idle speed? I have a faint idea that it somehow changes the pulse to the ICV, I'm supposing it results in a balance that has the ICV open longer.
>> 
>> Thanks
>> 
>> Alistair
>