Injector timing qns.

[Craig Pugsley]

Hi there, 
> 
> >     Rewording, will power output change much between full sequential
> >     and simultaneous injection, if you assume (as with L-Jetronic)
> >     that the fuel can "Hang around" in the intake while the valve
> >     is shut, or for optimum power should the fuel injector only be
> >     turned on while air is flowing into the engine?
> 
> At WOT sequential injection is worthless IMHO.  Your injectors will
> be spending considerably more time open than the intake valves.

That's basically what I was wanting to know. The main aim at lower RPM
is to get more torque (Mazda rotary = poor low down torque)

> > ii/ Does anyone have a graph of fuel flow/minute vs injector duty
> >     cycle at high RPM. (Concerning injector opening&closing times)
> 
> This is going to be a function of fuel pressure and different for
> every model of injector.

Hmm... I kind of mis-worded the question. What I'd like to know is
how linear the fuel flow vs injector time is (For a given
fuel pressure) when injector time is small, and if compensation for
this deviation is nessecary.

> > I'm in the process of building a basic analog injection computer so I
> > can get a feel for how the fuel algorithms work, then put it into a more
> > elegant microcontroller form (Probably 8051 based)
> 
> Doesn't sound particulary useful to me...  I think it'd be much more
> useful to put together a good little data logging system and then sample
> an OEM system in action.

I've already done some measurements of an ECU (aftermarket) and I'm
trying to put it into practice. I feel an analog system is easier to
"bash into shape" than microprocessor code, as I have only limited
micro programming experience. I have enough readings to make a fuel map,
but don't have enough info about how other inputs should affect the
injector time.

Regards,
Craig.