I need to change the vss to make my speedo work properly. I had TBI and now Im going carbed so I wont have an ecm. How do I figure out if I have electric or mechanical speedometer? If it is electric will I have to have an ecm to make it work?

 

If you take the ecm out you will need to just go get a mechanical speedometer if you dont have one already. If I'm not mistaken you should just be able to reach under the the drivers side under the car and right there on that side of the tail peice of your trans you should see a wire that goes into the back side of that tail piece. If its an electrical wire I would just assume its an electric speedo, if its a cable then you got mechanical.

Does anyone know the exact year of when they changed over to electrical speedos? I'm guessing 87 or so but I'm not sure. Here are all the links that I have found to try and solve my problem but thats a whole different ball game in the same park it seems >.< Anyway these pictures and words might help you out some.


<A HREF="http://www.transmissioncenter.net/SwapInformation.htm" ADD_DATE="1060295506" LAST_VISIT="1060295507" LAST_MODIFIED="1060295507">700R4 Transmission Swap Information</A>
<A HREF="http://www.73-87.com/garage/spdgears.htm" ADD_DATE="1060297089" LAST_VISIT="1060297089" LAST_MODIFIED="1060297089">Changing Your Speedo Gears</A>
<A HREF="http://www.gafba.com/articles/article.asp?tid=2" ADD_DATE="1060296220" LAST_VISIT="1060296220" LAST_MODIFIED="1060296220">Georgia F-Body Association</A>
<A HREF="http://www.hioutput.com/tech/speedo.html" ADD_DATE="1060295948" LAST_VISIT="1060295948" LAST_MODIFIED="1060295948">Installing an electric speedometer in your Firebird</A>
<A HREF="https://www.thirdgen.org/newdesign/tech/speedogear.shtml" ADD_DATE="1060295569" LAST_VISIT="1060295572" LAST_MODIFIED="1060295572">ThirdGen.Org</A>HREF="https://www.thirdgen.org/newdesign/tech/speedogear.shtml" ADD_DATE="1060295569" LAST_VISIT="1060295572" LAST_MODIFIED="1060295572">ThirdGen.Org</A>

 

You can still use stock electric speedometer after removing the ECM.

 

i just discovered a unit that dakota digital makes that will correct my speedometer problem. it is only 70 bucks so this is the route im gonna go. thanks for your help guys

 

Right, you're going to buy this magic box, to fix your already currently working speedometer

 

what Z28***** is trying to say...




the VSS sends the signal to your speedo.. and your speedo will continue to work, even with the computer out.

the signal goes from the VSS to the Speedo and from the speedo to the computer... so taking the computer out will not effect its operation.


same for most of the gauges.

 

MrDude's almost got it, in the TPI and V6 cars it does go to the ecm, but in the TBI it has a buffer box that gets the vss signal, then sends an output to the speedometer, the ecm and the cruise control box.

 

well i'll be damned. i had no idea that i didnt need the ecm to make the speedo work.

Thanks for savin me 70 bucks guys!

 

No Problem

This also works for TPI and V6 guys that may switch to a carb, but you have to wire the VSS buffer box in, its not hard at all.

 

So if i want to use the holley commander I can't use the VSS and therefore my crusie and vss will not work right but if use this buffer box they will work? Then how do i route it, go from vss to buffer box to cruise? I'm a bit confused