Date: Sat, 16 Nov 2013 19:00:13 -0800
Reply-To: Scott Daniel <scottdaniel@TURBOVANS.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Scott Daniel <scottdaniel@TURBOVANS.COM>
Organization: Cosmic Reminders
Subject: Re: Arduino and Vanagons
In-Reply-To: <52881BA9.7060608@gmail.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
a few more thoughts..
OK...the injectors fire when there is an ignition pulse , all 4 of them.
So ....for the one cylinder that happens to be just before TDC with the
spark plug firing ..
that cylinder's injection pulse is actually late for that cylinder.
the other 3 cylinders .....the injector squirt will be at some other
phase of the 4 stroke cycle.
It works out that things are moving fast enough ..( I read this years
ago in some paper discribing the system )
that injecting into the intake manifold happens continously in
pulses...and it all works out.
and they are not actually timed to intake valve being open say ..
or perhaps one cylinder is . .
while the other injector pulses happen in the intake runners at various
'not intake valve opening' times.
That's a more elaborate way of saying what I meant when I wrote that
injection events do not occur in a 'timed to engine position' way.
Scott
On 11/16/2013 5:28 PM, JRodgers wrote:
> Wow!
>
> Thanks Mark, for even more illumination on how things work in our
> mechanical beasts!
>
> This is all great stuff for those of us that don't know!
>
> John
>
> On 11/16/2013 4:24 PM, mark drillock wrote:
>> The injectors do fire in time with the engine position. All 4 injectors
>> fire once every hall pulse which happens every 180 degrees of crankshaft
>> rotation, so twice for every engine revolution. The ignition spark is by
>> definition according to engine position and the fuel injectors fire
>> based on the same triggering event that the ignition uses. Of course the
>> ECU adjusts the ignition point to optimize it. The ECU also cuts off the
>> injection pulses when conditions dictate, such as going down hill with
>> your foot off the gas, assuming your throttle position switch is
>> working.
>>
>> Mark
>>
>> Scott Daniel wrote:
>>> minor correction ...waterboxer injectors don't turn on 'every
>>> revolution' ..
>>> They are triggered continously in pulses...or in 'injector on time, in
>>> milliseconds of duration.'
>>>
>>> - as one big 4 part injector too btw. Called batch fire.
>>> Not sequential, not timed to engine or piston position.
>>> Somewhat crude.
>>>
>>>
>> .
>>
>
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