Having trouble figuring out where to wire up my VSS. On my 89, the purple and Yellow wires from VSS went to a yellow buffer box on pass side in dash. On LT1 it shows it going into "A" (Red) COnnector pins 31 &32. Then out on "B" (Black) COnnector pin 8.
How do I wire up the VSS? Do I need this buffer box? Car has Cruise.. or did until I started this ..

thanks.

 

Are you using the T-5 or an LT1 transmission?

The problem is that your VSS has a different output per mile than what the 4th gen is looking for. Depending on your VSS, you might be able to go into the LT1 program and modify the speedo settings to correct for this, but I'm not sure you will be able to turn it down enough. The other option is to use the Dakota Digital box. It will step the VSS signal up enough to be useable by the PCM. What you would do is get rid of the buffer box, as the DD box I believe has the correct output for the cruise control. You would then connect the DD to A31 & 32 on the PCM, and use the output from B8 to drive the speedo.


I just checked at Jags that run to see about your VSS and you are going to run into the same problem I did. Your VSS has a 2000 pulse per mile DC 5 volt output. The 4th gen VSS has a 17 pulse per driveshaft revolution AC output. There is no simple way to simply plug it in and have it work. What I ended up doing is leaving my stock VSS in the transmission to drive the speedo, and mounted a VSS out of a newer S10 (the same sensor pickup is used in just about all new GM vehicles) and mounted a 17 tooth sprocket on the driveshaft. Worked like a charm. Ultimately I'll use the computer to drive the speedo and mount the VSS in the transmission. PM for details if you want.

Another option I just thought of is to take the output from the buffer box that drives the speedo, hook this up to the dakota digital box, connect that to the PCM, and have the PCM drive the speedo. Just another alternative. Like I said though, there isn't going to be a real simple solution for you.

 

That's freakin brilliant! How about a picture? way cool man, way cool

 

Haha, thought you'd like that. Yeah I've got some photos coming pretty soon. I'll let you know when I get them.

 

I am using a T-5 form the 89..
This is a real drag.. everytime I turn around.. more money.. Oh well, lesson learned.. no more FI for me.... Where do you get one of these boxes and what are we looking at for $$ ?

thanks.

 

do I even need the pcm to see the vss?

 

Dakota Digital

 

Universal Speedometer Signal Interface SGI-5 $79.99? That the puppy?

 

Thats it. Check out the electronics or the Transmission board for help hooking it up. Also, I would get ahold of Dakota Digital and make sure its going to work like I suggested. I've never used it but from what I've read, putting it in after the buffer box should pose no problem.

 

YES!!!! Your car will run alright, but it definitely won't run like its supposed to without the VSS signal. I drove mine around for a year and a half without, so its not something you'll notice. But just about everything as far as the fuel maps are based off speed in some form or another.

 

ok.. so I can at least get the car moving.. I'm at my wits end with it.. I'm no mechanic and this is a little more than I can swallow.. but I'm slowing getting through it. Starting to cost me big time though .. should have bought the $534 cdn intake manifold for carb ... I was warned.... .. thanks for the help though..

So to recap.. I can just plug VSS Connector into VSS and leave wiring as is for now.. then when I get the DD box I can wire it into the PCM?

thanks.

 

Haha, yeah I spent probably double what I originally thought I would for mine. But yes, you can definitely leave it disconnected for now. Just be prepared, if you do drive it, when you're coasting down to a stop, be ready for it to die on you. Since the computer doesn't know how fast its going the Idle Air Control doesn't work right, so occasionally it will die coming up to an intersection. Since you've got the T-5, just drop it back into gear, let the clutch out, starts right back up no problem. Obviously I wouldn't suggest driving it like this for long, but it will be driveable without the VSS hooked up.

 

hang in there dude, keep reading the posts here and sooner or later you'll find a cheap way to do everything. I'll never go back to a carb.

17 tooth sprocket...... how the hell am i gonna top that one

 

Works like a charm and takes hardly any away from the ability of the driveshaft to slide in the rear trans seal.


Oh yeah, it only cost about $20 to do it the way I did. The junk yard gave us the speed sensor. The sprocket we had in the shop, but you could get that cheap.

 

pretty soon you'll be like me, you'll hate yourself if you have to spend money. All that hacking I did on my trans and all I needed was a 40 tooth sproket.....

 

I have to hang in now... I spent too much money .. I just want this thing to run.. go for a drive.. beat the *&^^ out of the tires and then park it and work the bugs out.. Right now, I don't even know if the engine runs good.. I got is at a salvage yard..

 

that's what I did. After a few crazy burnouts I put it back in the garage and now I'll hook up the brake switches and put the dashboard back in. Hang in there dude, we'll help ya

 

Its all worth it when you get it running smoothly and can roast the tires at will.

 

here is that reluctor wheel link..

http://www.jagsthatrun.com/Pages/Par...ctor-Diff.html