Cheap wasted spark upgrade

[Joseph Obernberger]

Hi - I'm working on something very similar.  I used a flip flop instead of a counter, and it worked pretty good, but I had some problems signal conditioning the reluctor signals from the distributor sensors.  Since then I've been told about the LM1815 chip from national semiconductor.  I'm hoping to use
that to condition those signals.
On my car (a 1991 MR2 turbo), the ecu sends out a 5 volt pulse that goes to the ignitor.  The trailing edge of this pulse triggers the ignitor to fire the coil.  The flip flop was setup to convert that signal into two longer pulses that would fire two separate ignitors (twin tower coils/ignitors from an
RX-7).
The ignition signal from the ECU fed the CLK on the flip flop, D1 was hooked to Q1(bar).  R1(bar) was connected to those two distributor sensors (through an OR gate) to ensure the flip flop stayed in sync.
Q1 and Q1(bar) were the outputs to the two ignitors.
You may find this page helpful: <http://www.fortunecity.com/silverstone/fiat/10/ddis1.html> and
<http://www.fortunecity.com/silverstone/fiat/10/ddis2.html>  He uses an MC3334P to build an ignitor as well.

                                                    joeo


bill.shurvinton at nokia.com wrote:

> Hi,
>
> I've been thinking about how to deal with dizzy bypass on my rotary and think that there is a very simple way to do wasted spark with an ECU designed for a dizzy using nothing more than a counter and a single sensor for #1TDC. It's so simple that I assume it has been done before, other than the eDIST.
>
> Is this the case?
>
> Rgds
>
> Bill
>

----- End of forwarded message from owner-diy_efi at diy-efi.org -----
----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org