[Diy_efi] Confused! Lost!

[Programmer]

>From the initial injector pattern, it doesn't appear to be actually
triggered the second time. The circuit doesn't go low. Could this be a ghost
spike from something else in the circuit ? Without knowing how the circuit
is designed, could this be a capacitive dump from the circuit in
anticipation for the next opening event ?
Did you check the higher RPM injector signal in a longer time frame ? The
second inductive kick might still be there.

Lyndon


----- Original Message -----
From: "Adam Wade" <espresso_doppio at yahoo.com>
To: "EFI" <diy_efi at diy-efi.org>
Sent: Wednesday, February 26, 2003 9:41 PM
Subject: [Diy_efi] Confused! Lost!


> Here's one for the experts...  Because it sure has
> stymied me.
>
> Kawasaki ZX-12R motorcycle.  Approx. 13 ohm injectors,
> so it's a sat driver, right?
>
> Welllll...  The idle trace from any of the injectors
> shows what very much appears to be a P&H trace...  A
> drop, then TWO spikes in close succession.  Like this:
>
> http://www.easttraining.com/images/Waveforms/gm_tbiv_p&h01.jpg
>
> This is somewhat irregular...  About 80% of the idle
> events looks like p&h, the remainder look like regular
> sat events, thusly:
>
> http://www.easttraining.com/images/Waveforms/efi_conv.jpg
>
> As the revs come up, the injector events pretty much
> all appear to be sat-type.
>
> WHAT ON EARTH gives?!  I was very much under the
> impression that driving a high-impedance injector with
> a P&H driver would result in the injector acting as if
> it was being driven by a sat driver.
>
> Can anyone shed any insight on this?  As much as I
> would love to offer the driver schematic, that is
> beyond my means; it's a proprietary design for
> Kawasaki, although I am led to understand by Kawasaki
> technical that they are using smaller engines with an
> ECU of the same design.  I am aware, though, that this
> does not preclude them from changing the driver
> circuit on one model.
>
> For reference, the bike is producing about 175 bhp at
> the crank at 10,500 rpm...  Which should mean
> something on the order of 22 lb/hr. for each injector.
>  Idle is around 1200 rpm.
>
> Is there some kind of trickery going on to help
> control idle injection events?  Any insight welcome!
>
> =====
> | Adam Wade                       1990 Kwak Zephyr 550 (Daphne) |
> |   http://y42.photos.yahoo.com/bc/espresso_doppio/lst?.dir=/   |
> | "It was like an emergency ward after a great catastrophe; it  |
> |   didn't matter what race or class the victims belonged to.   |
> |  They were all given the same miracle drug, which was coffee. |
> |   The catastrophe in this case, of course, was that the sun   |
> |     had come up again."                    -Kurt Vonnegut     |
>
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