KISS Fuel Injection via PIC. Any interest?

[Andrew W. Macfadyen]

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