VSS & 730 ECM

[Steve Ravet]

Mike Hoenes wrote:
> 
> I'm putting a TPI on my 355ci 85 S-10.
> I have poured over the archives and cant find an answer to this question.
> 
> How can I get a 730 ECM ( 91 F body automatic chip) to use the input from a
> 2000ppm VSS (tapping into the output from the solid state VSS used by the
> cruise control).  Near as I can tell, the F body program uses a 4000ppm
> signal from two inputs ( hi & lo) rather than a 2000ppm single input.
> I read that there is a select indicator, but no specifics were given about
> which byte to change.  Which pin is used for the 2000ppm input to the ECM?
> 
> Any alternatives beside getting a 4000ppm VSS  would be helpful.
> 
> Thanks!
> Mike

Mike, go to the JTR site and get the Chevrolet TBI & TPI engine swapping
manual.  I assume you already have the S-10 V* conversion book?  The
other one covers the electronics and generic TPI/TBI issues like wiring
harnesses in greater detail than the S-10 book, which mostly
concentrates on making it fit.

I have it, but it's at home.  I don't remember them mentioning a 4000
PPM VSS but that's not to say it doesn't exist.  Worst case you can put
a new VSS w/ mechanical cable connection in there, and get 4000 PPM for
the ECM and 2000 PPM for the cruise.  Or you might get a 4000 PPM cruise
module and forget the 2000 PPM altogether.

--steve


-- 
Steve Ravet
steve.ravet at arm.com
Advanced Risc Machines, Inc.
www.arm.com