VSS problems

[Tedscj at aol.com]

In a message dated 12/1/98 7:12:33 PM Eastern Standard Time,
n5xmt at bellsouth.net writes:

<< Also, What gear ratios were used in the stock app and what are in the new
app? >>

I don't know the original gear ratios for the stock app., but the car now has
a 3.54 rear and 15in wheels with 225/70 tires.
The original Astro van (from which the tranny came, but NOT the EFI) probably
had something more like 3.73 and somewhat smaller dia. wheels.
I read in the archives that GM rotates their speedo cables and VSS at 1000
rotations per mile.  I figure my rear end and large diameter wheel and tire
combo will result in rotations of the VSS somewhat less than that, but not 1/6
less!
This is also assuming that the Corsair ECU and Memcal also expect to see the 4
pulse VSS rotate at 1000 rotations/mile.... which would be 4000 pulses per
mile... which is what the manual states the ECM expects to see.  (assuming the
manual is correct... Chilton manual)
The more I think about it, the more I come to the conclusion that either the
VSS, the ECM or the SCAN TOOL is faulty.  Not a case of mis-matched parts.
I'm not using a vss with to few pulses (4 is max from what I understand)  The
transmission is GM and so spins the cable and VSS according to GM conventions.
And unless I had a 20 to 1 rear end (which obviously I don't)  it should read
a faster speed than 10mph for my real 60mph.
I don't need the VSS in perfect synchronization, just close!

Ted