Vss on 165 ecm help!

[Mike Rolica]

Yep, your s10 will be ready for optical vss,  you will have to drill and tap
the hole that the pickup sits in as my s10 is a 85 w/o cruise yep and here
is my bin file.
>From what I have heard, 89 uses electric Speedo and is alternating  ac at
4000pulses per mile where as optical is pulse dc .  Read in one of the
threads some where that on 4000 p/m electric Speedo the ECM is looking for 0
crossing i.e. ac  but at what voltage?  Maybe I will try to pull ECM with
open collector a 2n3904 npn Trans, so it acts  like optical pickup  i.e. dc
maybe I got some bad info.
  <<APYU3516.bin>> 

-----Original Message-----
From:	Vance Rose [SMTP:javer96 at snowcrest.net]
Sent:	Monday, September 20, 1999 2:43 PM
To:	gmecm at efi332.eng.ohio-state.edu
Subject:	Re: Vss on 165 ecm help!

At 10:42 AM 09/20/1999 -0400, you wrote:
>I have one last thing to solve on my tpi s10 project.  I have a mech
>operated speedo and the prom is for 89 firebird 350 tpi   (apyu)  It has
one
>wire -Brown for the vss.
>With the ign on I have 13v nothing connected.  I've tried the optical type
>but most I find are bunt out and I believe they are only dc pulse.  What do
>I need to send to the ecm?  What is it looking for in detail.  I have and
>inline gen. used on my 84 jeep grand wagoneer.  On my fluke meter it reads
>4v ac.  how can I make this work?   And I am sure I will shoot someone if
>they start telling me to modify the code of go buy something from JTR. ;-)
>
>thanks, Mike R
>
>Hi Mike

	In the middle of s-10 project myself. what year is your s-10?.
Believe the
optical unit using a transistor to "ground" the 12v coming from pull up
resistor in ecm. My pu is using an optical unit for vss.

	Would it be possible to get a copy of bin file?

Vance

PS: my s-10 is a 84 - came mech speedo - wiring diagram indicate the cruse
control uses a vss signal. still have to check my speedo to see if it will
accept an optical pickup.
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