The pulse width of the injector cycle will change based on air flow meter
and O2 sensor trim.
Many mutli-meters have duty cycle or PWM functions. Some can even record the
min and max values.

Dennis

-----Original Message-----
From: Vanagon Mailing List [mailto:vanagon@gerry.vanagon.com] On Behalf Of
Brett Ne
Sent: Saturday, November 16, 2013 9:11 AM
To: vanagon@GERRY.VANAGON.COM
Subject: Re: Arduino and Vanagons

Two more things to add to the list of things we'd like to know:

* What is the PWM duty cycle at 2000 rpm?(i.e. does the valve fully open, or
close, or something in between)
* What is the PWM duty cycle at full throttle?(maybe it opens the valve
fully to give that slight extra scrap of power to pass some of the slower
bicycles when going up a steep grade)

That last one will be tricky.  One person driving with the engine cover off
while another watches the scope.

On Fri, Nov 15, 2013 at 8:55 PM, Mike Miller <mwmiller6@att.net> wrote:

> David B probably has most, if not all, of these data being one of our
> prominent data freaks.
>
>
>
>
>   ------------------------------
>  *From:* Brett Ne <brettn777@GMAIL.COM>
> *To:* vanagon@GERRY.VANAGON.COM
> *Sent:* Friday, November 15, 2013 8:03 PM
>
> *Subject:* Re: Arduino and Vanagons
>
> GoWesty emailed back and declined to share their information, citing
> "that data is proprietary".  It really isn't, just as knowing the
> expected output voltage range of a healthy voltage regulator isn't
> proprietary.  Oh, well, it was worth a try...it just means a little more
work on our part.
>
>
> So, here's what we need to know:
> * The PWM duty cycle being feed to the idle air valve when:
>     --the engine is cold, the starter is engaged, and the coil is shorted
>     --the engine is cold & running
>     --the engine is fully warm & running
>     --the engine is fully warm & running with PS operating
>     --the engine is fully warm & running with AC on
>     --the engine is fully warm & running with PS operating and AC on
> *  The current draw from the idle air valve at a known duty cycle.(or
> feed it straight 12v and measure the current draw.)
> * The base voltage and the peak voltage coming from the Hall sensor
> The above items will need to be done by someone with a scope and a
> healthy ICU & idle air valve(and PS & AC).
>
> *  Which connector, 4/ST2 or 11/ST1, supplies the PWM power to the
> idle air valve. (and confirm that whichever supplies the PWM power,
> that the other is a ground connection.)
> *  What is the voltage at the coolant temperature sensor when cold and
> when
> 160 F.
>
> I think that this would provide all the information needed to design
> the circuitry and program the microcontroller to drive the idle air valve.
>
>
>
> And once a prototype is built, we will need a vict-- I mean
> volunteer-- to connect it to their rig for testing & fine tuning.
> Preferably in the Portland, OR area.
>
>
> --
> Brett in Portland, OR
> "Albert" '82 VanFox I4 Riviera
>
>
>

--
Brett in Portland, OR
"Albert" '82 VanFox I4 Riviera