Anyone have a working VSS Buffer that I can buy? I would also need if possible the wire connector that runs down to the VSS at the tranny. Or... Does anyone know where I can get one, besides the dealer? Thanks Andrew

Junk yard, full size vans in paticular since they are easy to get under. I was just there today, if I had seen this post before, would have looked for you. From what I've read there are a couple of different ones. A tranny shop shouild be able to help you out as well.

Didn't you get a '91 or '92?

I think the buffer is in the ECM on the SD cars.

Acceld Z
I got a '91 Z, but the power train has been change to carb/HEI so the ECM has been put in a box along with the whole TPI set up. The two ways that I can get my speedo to work are to get a VSS buffer which was how all the 5.0L TBI cars were equipped in '91, or to go and buy the Dakota Digital SGI box so that the VSS inputs can be "translated" to the speedo. (These are the ways that have been recommended)

Hey Half Inch,
Which years of full size GM vans are we talking about?, and where would I look? (under the dash - right or left side...)
The GM part# that I need is 25071437
Thanks guys,
-Andrew

Around the same year of your car give or take -5/+5 years. Just trying to give you a hand, don't know the whole way thru myself.

I have a similar problem. I was just going to buy the Dakota Digital box to avoid the driven gear hassle. Check this thread out.............

http://www.thirdgen.org/techbb2/show...hreadid=186037

Acceld Z
that's some good stuff as well. Thanks
IF i can't get my hands on a used buffer, Not sure what to do... The Dakota Box is $80US and I have found a new Buffer for $115.CND. The box is more versatile, but I have been told it is a PIA to set up. THe Buffer it would seem is the easier install/calibrate. I really don't want to hack at the wiring harness behind the dash - this makes a mess even if you do things right, So the buffer "may" be a better bet - but from the looks of things, even to hook up the buffer will require some cutting and soldering.
Any thoughts or opinions?
You won't have any gear drive hassels with either the Box or the SGI unit. The gear driven speedo's were axed beforethe '91/'92 models - well before. (Was it in '87 that GM switched not sure...)
-ANdrew

Well I finally got out to a auto wrecker and picked up 7 VSS Buffers, and the harnesses. $20.00 for all of it - GM wanted $114.00 for a new one, and if you go the Dakota route, their system is worth $80USD.
I would like to thank the guys (HalfInch, AcceldZ etc...) who helped me out, I got my speedo working - just like new, no hacking ect..
If anyone else needs a hand, I would like to pass along that beside just TBI F bodies, and the 6cylers, I found a pile of the Buffers on mid 80's caddies with TBI - passenger side.

Hey AcceldZ if you still need to get your speedo working I can pass you along something through the mail or ?? just pm me. This project was a breez - just make sure you have a schematic of the gauge harness to aid in wiring up the buffer.
Thanks again guys
-ANdrew

Could one of you provide me with the wiring diagram for the 4out.buffer. I'm upgrading to a tuned port and need to provide the ECM with the proper input. I already have the module, just not all of the connection points.

Here is a link with the pics :http://www.thirdgen.org/techboard/el...s-cluster.html (80s cluster to 90s cluster)
If that doesn't work, here is scan of the same info.
I have also added the schem diagrams for the ECM wire harness for TPI cars and the VIN E (tbi v8 cars) VSS wire schematic.
One thing tho, wire colour (and possible circutry) may be different from what I have posted. The two schems are for a '91 TPI and '91 TBI car -
depending on the year of ECM that you intend to transplant into your car the wire colours may be different and in different pin locations on the female ECM connector (or if you are splicing into the wire harness, then obviously on the male end...) From what year of F body is the ECM comming from?
-Andrew

Exactly what I needed. Thanks!

Does anyone have a VSS Buffer I can get.
Thanks, John

Check your pms. I still have a few.
-Andrew

I need a VSS sensor itself.mine doesnt send signal from the trans at all.tranny shop said the gear is intact and works properly but the sensor is shot.a new one is almost $150 :O