I want to make a point here about open program source code verses
proprietary computer programs. Open source code means that the source code
is published for all to read. The open source Linux OS is four or five times more
stable than Windows XP. I use both daily. I run this newsletter off Linux
and I have a relatively new Windows XP computer that runs Rhino. Thousands of
programmers have read the Linux source code and have discovered bugs which were
fixed immediately. With proprietary computer programs only one or two people
can read the source. One is the programmer that wrote it. I know about this
as I have written thousands of lines of assemble language code myself
over a period of 20 years and started designing computers in the middle
70's to run it on.

Now for all you people that are trying to implement EFI I recommend you
go with an open source electrical design and open source software.

Namely the Megasquirt. Megasquirt has a long history of open source
and thousands of people have used it and hundreds of engineers and programmers
have reviewed the design and read the source code.
http://www.megasquirt.info/
http://www.glensgarage.com/catalog/?gclid=CJL7s6TcmI8CFUtyOAodnRuTfA
http://www.diyautotune.com/
http://www.bgsoflex.com/megasquirt.html
http://www.msefi.com/
http://en.wikipedia.org/wiki/MegaSquirt

Just a few of the many web sites dedicated to Meagsquirt

Obviously the stock computer can be made to work as proven by Perry Mick
but there maybe some quirk in there that has not shown up yet.

If I were designing an EFI. I would keep it super simple. Single chip computers
are dirt cheap. What I have in mind is simple multi chips
modular systems that did only one simple job. One job per chip. The program can be
written in hours and  not months. Any one  system built and tested in less than
a month. One for fuel another for ignition and a third for display. Perhaps
another for turbo charger control. It makes for simple understanding of what
the hardware and program does and how it does it. These systems can share sensor
inputs. If both your ignition and fuel injector goes out it is probably
the crank angle sensor.

This also off loads the software jobs so it does not matter how fast
the code executes. Any BASIC interpreter and chip can handle the single simple job.
The code is much much easier to write and maintain as there are NO unforeseen
side effects on other modules. The open source code is so simple it is easy for
anyone to understand and help you trouble shoot and repair.

However me personal I still prefer mechanical fuel systems.