VSS importance

[Jeffery Flanary]

Thanks for the reply, this list is great.  Although 98% of it is over my
head, i am slowly learning.  Thanks again.  Jeff

----------
> From: Bruce Plecan <nacelp at bright.net>
> To: diy_efi at efi332.eng.ohio-state.edu
> Subject: Re: VSS importance
> Date: Tuesday, September 29, 1998 11:34 PM
> 
> 
> 
> >Hello all, i am new to the list and am getting some very useful info.  I
> >have an 87 S10 Blazer with 8" of lift and 33x12.50's.  I installed a 305
> >TBI V8 which originally used a 16136965, but have since changed to a
> >1227747.
> 
> I'd be very interested in that 16136965, can even promise a nice,
> home, and most of it's work/life will be spent indoors.
> Cheers
> Bruce
> 
>  When i first started the swap, i wasn't sure if i'd need the VSS
> >that hooks up at the transfer case, or if i could use the sensor that is
> >built into my speedometer.  I purchased a Cyberdyne speed sensor and a
> >calibration box.  A friend of mine used this setup on his 86 S10 TPI
with
> >the 730 computer.  After i realized that my speedo sensor worked, i gave
> >him the Cyberdyne stuff for spares.  Anyway, thanks for the good info
> 
> Lots more about programming the 1227747 in Programming 101
> >
> >P.S.  When i switched to the 747 computer, i changed the prom only.  A
> >friend who sold his truck gave me a power chip he had for an 88 Chevy
TBI
> >350 auto.  I am running this chip even though it is a 305.  The
hypertech
> >guys said the only difference was the injector pulse width and
recommended
> >i buy the 305 chip, but the truck runs great with the 350 chip.  Also, i
> >didn't change the calpak.  The computer was in an 88 Astro Van with a
4.3.
> >I have heard that it only uses the calpak in limp in mode.  Is this
true?
> 
> Yep, just a nurse ya home item.  Might try unplugging the MAP, and
> try to drive it, just to know ya can.  The netres is about $8.
> 
> >Sorry to be so elementary on such a high tech list, but i am just
getting
> >started.
> 
> Heck, wearing Cone Shaped Hats around here (my house) is
> an everyday thing.   About the time ya think ya got it it slips
> away (at least for me)
> Again
> Bruce
> >
> > Thanks, Jeff
> >
> >----------
> >> From: Bruce Plecan <nacelp at bright.net>
> >> To: diy_efi at efi332.eng.ohio-state.edu
> >> Subject: Re: VSS importance
> >> Date: Monday, September 28, 1998 10:35 PM
> >>
> >>
> >> -----Original Message-----
> >> From: T Hergen <thergen at svn.net>
> >> To: diy_efi at efi332.eng.ohio-state.edu
<diy_efi at efi332.eng.ohio-state.edu>
> >> Date: Monday, September 28, 1998 9:34 PM
> >> Subject: Re: VSS importance
> >>
> >> These aren't the best of answers maybe some one can chime in, please..
> >>
> >>
> >> >The x2 or /2 is half the puzzle.  I'm don't know what the vss sensor
> >> >outputs or the ecm vss input expects.  Does anyone know what range of
> >> >voltages a vss sensor will produce?
> >>
> >> It's like a motor with a gear on the end, just a little A/C generator.
> >> As I recall they can light up a LED.  I think the words zero crossing
> >> was used.
> >>
> >>  Does anyone know what the minimum AC
> >> >voltage swing is needed on the various vss inputs?
> >>
> >> The 730 type of ecm at 4000ppm is A/C. and the 2000ppm is
> >> a pulsed DC.
> >> >
> >> >These same questions will come up if a phase locked loop is used.
> >> >
> >> >Bruce, in your 555 thru a cap to vss experiment, was the 555 powered
by
> >> >12v or 5v?
> >>
> >> Between my eyes, and lighting I'll have to look again in the am.
> >> There is a 78XX..
> >> Cheers
> >> Bruce
> >> >
> >> >Thanks,
> >> >Tom
> >> >
> >> >
> >