KISS Fuel Injection via PIC. Any interest?

[rhuish at goldrush.com]

> 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:
> 
Interesting project, I've been planning to replace the SUs' with a 2.2 TBI 
(67 MGB-GT), but the thought of separate injectors interest me.

> - To replace SU HS4/HIF4 carbs, which are pretty minimalist pieces of
> equipment.
>
Sounds right, I get real tired of the weekly "Oil the carbs"! I expect fuel
economy would also benefit.
>
> - Batch fired injectors.  Software would work for any number of cyls.
>
I'd rather fire them in pairs. The minimal cost of additional components hopefully
would be offset in reliability. 
>
> - 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
> 

Bob Cuda-65 - Angels Camp, Calif.
cudabob at workmail.com
http://www.goldrush.com/~rhuish/