KISS Fuel Injection via PIC. Any interest?

[Simon Bosworth]

Andrew,
I plan on making a pair of runners with one injector in each.  These would
connect to a plenum with an Escort TB and
MAF sensor.  Another possible approach is to make two TBs with injectors in
them and use MAP.  In either case I am thinking of retaining the original SU
manifold; for heat insulation and the balance tube.

Cheers,
Simon

Andrew W. Macfadyen wrote:

> Should help with the low speed mixture distribution  problems on the B
> caused by the siamesed inlet ports, they often idle with just 2 cylinders
> doing most of the work.
> You could use a side draught  Weber DCOE type manifold  for which
> aftermarket throttle bodies which are available --  but you would have to
> use 2 injectors only  ie; 1 injector for the front pair of cylinders and
> one for the back.
>
> P.S. True the SU carbs were mimimalist but they were clever stuff and a
> great advance over what was available  back before WW1 when they were
> invented and they stayed the course until very recently.
>
> Simon Bosworth wrote:
>
> > Hello all,
> > with all this sudden interest in PICs, I am wondering if anyone else
> > would be interested in a KISS (Keep It Simple Stupid) EFI based on a
> > 16C73 PIC ?  I am planning to do one for my 74 MGB.  The 'design
> > guidelines' would be:
> >
> > - To replace SU HS4/HIF4 carbs, which are pretty minimalist pieces of
> > equipment.
> > - Batch fired injectors.  Software would work for any number of cyls.
> > - Inputs would be TPS, Coolant temp, MAF or MAP, Air Temp ? and RPM
> > signal picked off distributor.
> > - Injector pulse width would be based on maps stored in EEPROM.
> > Possibly using byte-wide EPROM + some interface 'glue' chips to enable
> > the PIC to access 'external memory', which normally doesn't do.  If
> > processing time allows a serial EEPROM would make interfacing dead
> > simple.
> > - The chip includes a serial port to provide a handy 'user' interface.
> >
> > This should be quite a simple system hardware wise.  It could be
> > prototyped on a SIMSTICK type board, ($6 from Wirz electronics).
> > The batch fire method removes the need for special pick-up wheels and
> > sensors; there is no need for synchronisation.
> > Use Sandy's very nice injector driver board for low impedance
> > injectors.  High impedance types would be simpler.
> >
> > It should provide at least as good a performance as any analogue system
> > without any greater hardware complexity.
> >
> > Potential points against such a system are:
> > - Developing the fuel maps may be a problem, at least for the first
> > person to try it for a particular engine :-)
> > - You may still need some sort of I/O board to condition the input
> > signals.
> > - Would it really be that much simpler and/or cheaper than the EFI332
> > system? and would it divert resources away from the EFI332 project when
> > it really needs all the help it can get?
> >
> > Looking for feedback,
> > Simon
> >
> > --
> > ------------------------
> > Simon Bosworth
> > simonb at primenet.com



--
------------------------
Simon Bosworth
simonb at primenet.com