[Diy_efi] northstar DIS and what it all means ?

John Stricker jstricke at rwisp.com
Thu Jan 9 03:59:24 GMT 2003


No, don't have it.  I haven't found anyone that has it and is willing to
share.  There is one person that has hacked the code on the '95's (IIRC)
that has modified it for the lower HP version of the engine and done a
transmission delete on it so it will run a manual transmission but it ain=
't
me.  He is willing to burn chips for people with that application, althou=
gh
I don't know at what cost.  All I have is the shop manual, Mitchell on
demand, and some other resources that aren't geek speak.  At the moment, =
I'm
working on the mechanicals of the engine.  Computer will come later.

John Stricker

----- Original Message -----
From: "Tom Sharpe" <twsharpe at mtco.com>
To: <diy_efi at diy-efi.org>
Sent: Wednesday, January 08, 2003 9:32 PM
Subject: Re: [Diy_efi] northstar DIS and what it all means ?


> do you have the code?  disassembled and commented? copy please. Tnx Tom.
>
> John Stricker wrote:
>
> > I can't tell you what the engine will do on the fuel side in the even=
t
of a
> > cam sensor failure, but I'm trying to figure it out on the trouble
shooting
> > charts.  The cam sensor is used to provide the ICM with cylinder #1
firing
> > order information to control the SFI.
> >
> > As for the dual crank sensors, the crankshaft has a reluctor ring wit=
h
24
> > evenly spaced notches plus eight additional notches used for synch.  =
The
two
> > sensors are spaced so that the signal of the lower one lags the upper=
 by
27=B0
> > of rotation.  The ICM first counts the number of the lower pulses
between
> > every two upper pulses.  There can be 0,1, or 2 lower pulses between
upper
> > pulses.  When the ICM sees 0 lower pulses between upper pulses, it
starts
> > counting lower pulses between upper pulses.  when it counts exactly 4=
,
it
> > synchs the ignition on the very next upper pulse.  If the ICM counts
over 4,
> > it waits for another '0' lower pulse between upper pulses to start
counting
> > again.  This allows the ignition to synch and fire the fist spark plu=
g
> > within 180=B0 of engine revolution.
> >
> > I suspect the engine will continue to run in a limp home mode, althou=
gh
I'm
> > not sure, because the purpose of the dual sensors is to provide quick
synch
> > and starting and to allow the ICM to maintain ignition synch even if =
one
of
> > the three sensors is bad.
> >
> > If it will help you, I can email the ICM input and output pulse chart=
 to
> > you.
> >
> > Hope this helps.
> >
> > John Stricker.
> > ----- Original Message -----
> > From: <Djfreggens at aol.com>
> > To: <diy-efi at diy-efi.org>
> > Sent: Monday, December 30, 2002 5:32 PM
> > Subject: [Diy_efi] northstar DIS and what it all means ?
> >
> > > i got my hand today on a northstar v8 dis ecm sehcmatic. i was look=
ing
at
> > it
> > > and wondering if the dis doenst see a signal for the cam what does =
it
do
> > ??
> > > would it go into a limp home mode and fix timing or would it simply=
 go
> > into a
> > > batch fire mode. also it has 2 crank pickups what for. btw this is =
for
a
> > 94
> > > system. ive been reasearching this for use with a 727 and $8f code.
its
> > looks
> > > like a good system to pirate if itll work. i would imagine that gm
kept
> > the
> > > dweel control strategy. but as for the 24x siganl. what would you s=
end
the
> > > ecm the 24x or the 4x and if you disabled the cam would the signal =
for
24x
> > > revert 6x ?? im hoping somebody out there has some answers. guidanc=
e
and
> > help
> > > apprciated.
> > >
> >
> > _______________________________________________
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> > Diy_efi at diy-efi.org
> > http://www.diy-efi.org/mailman/listinfo/diy_efi
>
>
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