[Gmecm] Re: Running V8 with $A1 DIS code

[William Lucke]

The information contained in the Aurora shop manual laid out a diagram of 
all signals. It called out the 4x as high for two pulses of the 24x (5* 
BTDC - 25* ATDC), then low for 4 pulses of the 24x.
The gentleman on whose behalf I'm posting here scoped it an confirmed 33% 
DC. Since he did his own wiring harness (a large and complicated task in a 
N* Fiero), I assume he's sufficiently competent to probe the correct pin. 
My manual confirms pin C.

Ok, what does the reference signal for a 4 cylinder look like? Where 
relative to TDC does it go high or low?
If we used a 4 cylinder mask and just doubled base timing and timing table 
entries... that might work. What mask would you recommend for getting started?


Will


>Date: Sat, 16 Apr 2005 19:22:41 -0600
>From: "WopOnTour" <wopontour at hotmail.com>
>Subject: Re: [Gmecm] Re: Running V8 with $A1 DIS code
>
>Really?
>Every N* IGN REF I've ever scoped was 50% (toggles every 45 degrees to
>create a 4X) The only IGN REF I've ever known not to be 50% is the 4
>cylinder engines- which are 60/120 (33%) What pin are you scoping, should be
>PIN C (sometimes labeled "fuel control" in the schematics)
>Regards
>WOT
>
>----- Original Message -----
>From: "William Lucke" <william.lucke at highspeedlink.net>
>To: <gmecm at diy-efi.org>
>Sent: Saturday, April 16, 2005 6:46 PM
>Subject: [Gmecm] Re: Running V8 with $A1 DIS code
>
>
> > That's a little clearer... thanks.
> >
> > So the reference signal from a V6 coil pack is 50% duty cycle, right?
> >
> > I think we've found the problem... the Northstar reference signal is 33%
> > duty cycle.
> > So on a shot pulse, the RPM calculated for that pulse would be 1.5 times
> > actual RPM and the RPM calculated from a long pulse would be 2/3 actual
> > RPM. The calculated RPM would bounce back and forth between these values 4
> > times per revolution... AIUI.
> >
> > Any way to get V6 DIS code--any mask--to run with this coil pack?
> > How does a 33% DC 4X compare to the DRP's from a distributor?
> >
> >
> >
> > Will
> >
> >
> >
> >>From: "Programmer" <lwester at lincsat.com>
> >>Subject: Re: [Gmecm] Re: Running V8 with $A1 DIS code
> >>To: <gmecm at diy-efi.org>
> >>Message-ID: <002001c541df$c8dbaf00$4250050a at WESTER2>
> >>Content-Type: text/plain;       charset="iso-8859-1"
> >>
> >>
> >>No coil pack event every 60 degrees--measurement event, yes.
> >>My stupidity apologies to the masses...brain got interrupted by typing
> >>again. By comparing the time between pulses on the DIS V6, after seeing
> >>the
> >>7th slot (sync pulse), every other trigger slot is skipped. The second
> >>pulse
> >>fires #2/#5, 4th fires #3/#6 and 6th fires #1/#4. There is no coil firing
> >>event for the other trigger slots--although they're still
> >>monitored/measured. This actually provides a better timing advance
> >>signal/measurement.
> >>Anyways...this is correct for the '730.
> >>
> >>Over and out.
> >>
> >>P.S. Take a look at the LS1 code, someday...you'll see some pretty wild
> >>timing values.
> >>
> >>Back to lurk mode...
> >>
> >>Lyndon.



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