DIS, and 68HC12

[Don.F.Broadus at ucm.com]

If you use a  older Ford distributor, replace the module with a late model 6
pin module. The 6 pin module has a PIP (profile ignition pick up) output
that can be used for injector and ignition reference pulses. The SPOUT input
to the module controls the engine timing. If you place a metal flag at
around 60 degrees advanced on the harmonic balancer that interrupts an
optocoupler, you can use this pulse and the PIP pulse to control and monitor
ignition advance. Base timing by the ECU is usually 26.5 degrees at idle
(4cly)
45 degrees is possible at light load, use the MAP output as a load monitor.
I have been working on a stand alone circuit(non micro)to control IAC,timing
and injectors to run an engine on a test stand. I will post any new data as
I find it.
 
Don   

> -----Original Message-----
> From:	Jurgen Hartwig [SMTP:gt0003a at prism.gatech.edu]
> Sent:	Tuesday, April 27, 1999 1:36 PM
> To:	diy_efi at efi332.eng.ohio-state.edu
> Subject:	DIS, and 68HC12
> 
> Hi all, this is my first post to this mailing list.  I've been hiding
> for some time enjoying the great wealth of information spread forth by
> the likes of Greg Hermann and others.
> 
> 
> I am working on a distributorless ignition system, and while it is not
> purely FI related, I am hoping that the information I pick up from this
> project will help me immensely with later FI projects.
> 
> Basically, my friend and I are designing a system around the Motorola
> 68HC12 series microcontroller.  It is similar to the system that Tim
> Drury has outlined on his website.  Now, I'd like to interface with some
> of you that have had experience with the 68HC12 or 68HC11.  We need to
> find some development boards or similar, and I have found two at around
> $100.  Is it easy to build my own board?  The HC12 has 110+ pins, so it
> sounds like it would be tough.
> 
> We are planning on using the Motorola chip to permit fully adjustable
> timing curves, and thanks to the archives, I've found a large amount of
> data pertaining to adjusting the curves.  The system will be waste
> spark, with junkyard variety coil packs and wires.  Does anyone have a
> source or list of vehicles that came with coil packs?  I am heading down
> to a U-Pull-It yard here in Atlanta this Friday, and I'd like to know
> what to keep my eyes open for.  Any ideas on cost for wires and coil
> packs (need two minimum for first project)?
> 
> Also, the first car we are trying this system on will be a '92 Ford
> Probe.  Does anyone know where we can get timing curves for the
> distributor?  I suppose I should call the dealer, but I wonder if there
> is anything online or printed that I could consult.
> 
> Lastly, the final version of the distributorless ignition system will be
> crank fired, but for simplicity I am going to use the distributor to
> trigger the MCU.  I was thinking of grabbing an old distributor from a
> junked Ford Probe and super gluing the centrifugal advance, and
> disconnecting the vacuum advance.  Then we can use the existing hall
> effect sensor as the trigger, but I don't know if the four lobes will
> provide enough timing resolution.  Any thoughts or ideas?
> 
> We are using a GM MAP sensor as load input for the MCU.  The MCU will
> calculate timing vs. RPM vs. load.  The timing curve will be adjustable
> from a laptop computer through the serial interface.  Anything I'm
> missing here?
> 
> I apologize for the great length, but I value your opinions greatly and
> would appreciate any guidance on our first project.
> 
> 
> Take care
> Jay
> -- 
> When you were born you cried
> And the world rejoiced.
> Live your life so in death you rejoice
> And the world cries.