Surely less fuel, same volume of air = weak mixture = pinking = holed
pistons?

But form my experience, if you do the opposite to a diesel, you get load
more power and it works with petrol engines but not as dramatically.


Lester Wilson
Crownhill Associates Limited
The Old Bakery
New Barns Road
Ely, Cambs.
CB7 4PW

Tel: +44 (0) 1353 666709
Fax: +44 (0) 1353 666710
-----------------------------------------
www.crownhill.co.uk
www.towitoko.co.uk
www.Edsim2000.com
----------------------------------------

----- Original Message -----
From: Peter Mcalpine <mcalpine@GME.NET.AU>
To: <PICLIST@MITVMA.MIT.EDU>
Sent: 19 May 1999 02:05
Subject: Re: Limit fuel injector pulses


> Hi Jon,
> I think you are going the wrong way about the control of injectors.
> A better way to trim injector duty cycle is to modify the inputs
> the cars ECU gets, ie vary the signal level from the air flow
> meter + or - an amount.. Trick the ECU into delivering less fuel.
>
> Regards
> Peter Mcalpine
> petermca@ozemail.com.au - www.ozemail.com.au/~petermca
> mcalpine@gme.net.au - www.gme.net.au
> www.wrx.org.au
>
>
> ----- Original Message -----
> From: Jon Petty <Phxsys3@AOL.COM>
> To: <PICLIST@MITVMA.MIT.EDU>
> Sent: Wednesday, 19 May 1999 9:56
> Subject: Limit fuel injector pulses
>
>
> > Hi everyone
> >
> > I want to use a PIC or even a stamp to manipulate fuel injector pulses,
> > mainly reduce the pulse width. I really don't want to utilize individual
> > injector drivers (for sequential injection systems) that will complicate
> the
> > project. As you are probably aware sequential systems usually use an
> > individual driver for each injector. One side of all the injector has a
> > common 12v source to all injectors and the individual drivers (sink)
> control
> > the ground.
> >
> > I was wondering if it is possible to modulate the 12v power line which
is
> > common to all injectors. For example say the PIC measures the previous
> > injector pulse at 5 msec and I want the injector to pulse 2.5 msec on
its
> > next fire. Could I allow the injector to fire normally and cut the power
> at
> > 2.5 msec (to shut off the injector) and turn power on again in time for
> the
> > next injector firing? I am not sure what effect the  rise and fall times
> of
> > the power supply will have on injector firing or operation.
> >
> > If this is possible, I would just need one power control circuit to trim
> 4-8
> > injectors. I could easily use a PIC to measure the pulse, allow the
> initial
> > injector firing to happen on schedule and trim each injector by
> controlling
> > the power source which is common to each injector.
> >
> > What do you think?
> >
> > Any comments or suggestions for hardware that could accomplish this?
> >
> > Thanks in advance
> >
> > Jon