hall sensor simple questions

[nacelp]

GM has used the distributor pulse (only) for EFI for hundreds if not
thousands of applications.  They set the intial timing at say 6d  BTDC, so
that in a faliure mode there is enough timing for the engine to at least
sorta run to get you home.  They use a matching number of distributor
reference pulses to the number of cylinders.  (also, since it's reluctor
style there is some self advancing characteristics that help with that).

Now for SEFI (timing or fuel control), then you need an addition sensor to
sync things to number 1, or what ever your reference cylinder is (not all
engines are built on number one, is why I mention that).

Now for individual cylinder timing control in a feedback system (ie knock
sensor), then you even to sync the knock sensor to cylinder, and/or measure
crank shaft accleration rates.  Which means a very high resolution sensor.
Grumpy


----- Original Message -----
From: Swayze <kswayze at bellsouth.net>
To: <diy_efi at diy-efi.org>
Sent: Monday, March 20, 2000 9:58 AM
Subject: Re: hall sensor simple questions


> so, if using a dissy for the timing pulse, you would still need a TDC
> reference (either missing or extra tooth(notch)  or extra
> sensor(crankshaft?)
> byE
> Mike
> Swayze
> mswayze at truswood.com
> kswayze at bellsouth.net
> ....................
> > ??. Accuracy (at least in the mechanical sense), is a function of the
> number
> > of references, not number of sensors.  You can do equally well with
crank
> or
> > cam, the only time you need both is in SEFI (meaning timing or fuel).
If
> > you want to measure crankshaft accleration rates accurately then you
need
> a
> > crank sensor, since there is always "gearing" for the distributor, and
> that
> > alllows for slow, and erratic signaling for that level of resolution,
> > needed.  You can get by with dissy, but the resolution of input, and
> > filtering gets more complex, and hence more room for error.
> > >
> ....
>
> --------------------------------------------------------------------------
--
> To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the
quotes)
> in the body of a message (not the subject) to majordomo at lists.diy-efi.org
>

----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org