Scamo-2.8

iTrader: (16)

I've come so far yet still so far to go...
I have a 1989 2.8 5 speed car and I swapped in a 1990 5.7 with the computer and engine harness (Major re-wiring to make it work with the 89 under dash harness...) I also added a V8 five speed off of a 1984 camaro. I have finished everything except for one thing.. The speed sensor. The 90 requires a electronic speed sensor but my 89 v6 had the optical cable behind the gauge cluster, speed sensor. What do I do?! Can I install a 90 gauge cluster and will it work (with a bit more re-wiring of course) with my 89 under dash harness? Or is there something else that I can do? Something to by pass the speedsensor? Please I need help!
My buddy's 1990 Cavalier had a speed sensor that had both a plug and a cable but GM told me that there was nothing like that available for the Camaros....
The Camaro seems to run fine without it hooked up but the check engine light keeps coming on after a few minutes.. I can pull the bulb for now but with a new engine swap I'd rather have that light working just in case.

scooted45

I took an 88 Gta tranny (700r4) and rebuilt it to put it in an 86 iroc. The 88 had an electric speedo. The 86 did not. I found that the 86 mechanical sending unit bolted right in. Maybe you could do the reverse.

Scamo-2.8

iTrader: (16)

I wish that would work but it won't.

five7kid

iTrader: (14)

You should be able to put a T-5 transmission-mounted speed sensor in. Not sure if they're available from the dealer - have you checked?

kal

It can work. I did the same thing on my 83 firebird. It wasn't hard at all once some pointed me in the right direction. The first thing you need is the vehicle speed sensor (vss). I got mine from gm parts direct. http://www.gmpartsdirect.com/results...umber=10456087 That one is for a t-5, the on for the auto tranny is different. The next thing you need is a vss buffer, which is a little yellow box that sends the signal from the vss to the gauge and the computer. I got mine from the classifieds on this site. Do some research and find out if there is a difference between cameros and firebirds. It is possible cause I did it. Here's some links that might help. Let me know if you need any more help.

https://www.thirdgen.org/techbb2/sho...hreadid=275439

https://www.thirdgen.org/techbb2/sho...hreadid=275263

Scamo-2.8

iTrader: (16)

Kal, thanks for your help. I understand what your saying and but we're talking bout different things.
The VSS in the 90 Camaros got rid of the buffer. The VSS (on the tranny) wires run straight to the computer (which acts as the buffer I guess) and from there it sends a 4000 ppm signal to the speedo.
The problem is, is that I am doing almost the same as what your doing. But you see I don't want to change my dash, I want to leave the 89 cable driven speedo, gauge cluster in the car. But the computer is out of a 90 and it wants a signal from the 90 transmission mounted VSS not the 89 optical VSS. I want to continue to run the cable and have an electronic tranny mounted VSS as well. I guess I want my cake and eat it too..... I don't know if it's possible.
The easy thing to say would be, well just put a 90 gauge cluster in, but they changed the gauge clusterin 90 so the dash would have to change and then 'd have to re-wire the under dash harness to work with the 90 gauge cluster, and who knows what other problems I would run into (air bags, etc.). Was it hard to wire in your electronic gauge cluster?

From factory It works kinda like this:
90 CPU + 90 Electronic tranny mounted VSS + 90 Gauge Cluster = VSS signal to CPU and Working speedo
89 CPU + 89 Optical Cable driven Gauge mounted VSS + 89 Gauge cluster = VSS signal to CPU and Working Speedo

However I'm doing trying to do this:
90 CPU + ????????????? + 89 Gauge Cluster = VSS signal to CPU and working speedo

I don't know how else to explain it... Do you see what I'm saying? It's kinda confusing I admit, but I'M SO CLOSE!!!

Klortho

There is still a VSS buffer box on the cars that have electric speedos, the yellow box on the back of the mechanical speedo is actually the buffer box that goes to the ECM. You will need an electric speedo from the year they changed the dash (think it was 90 or 91) and the associated wiring and buffer box for the speedo to work properly and get rid of the code in the ECM.

kal

ohh sorry, now I uderstand what you are tryin to do. This is going to be very very fun. I have never heard of anyone doing this before but where ther is a will there is a way. I have some ideas for you.

#1: you hook up your gauge with the cable the your optical vss buffer will give you a signal. then you wire that signal to a calibrater box that will covert that signal to 4000 ppm which is then wired to your computer. This one is kinda iffy because becaus the box is not for use with antilock brakes. Here is a link for a calibrater. http://www.dakotadigital.com/Detail....rtNumber=SGI-5

#2 You get a speedo cable for cruise control because it should split into 2 cables some where. You run one to your gauge and the other one you run to the electric vss. you would probaly need to weld it to end and mount the vss so it is sturdy under the hood or dash but it should turn the vss the same as if it was monted in the tranny. then hook up the wires to the vss buffer for electric gage and run that to your computer.

I hope this helps or at least gives you some ideas to get you going. It wasn't too hard to wire up the dash for me. What I did was follow all the pins on the old dash and wright down what all the pins go to on the gauge cluster. then do the same for the new cluster and write those down too. then compare the 2 and see which ones need to be moved or added. Let us now how it works out.

Scamo-2.8

iTrader: (16)

Finally someone who understands what I'm trying to say!
It's funny Kal, I couldn't get access to the site yesterday to see if you wrote back with another idea due to the fact that the site was changing servers. So I was flipping trough some magazines and found a place called TPI Gauges (www.tpigauges.com) and called them. The guy there was really helpful, listened to my speech about the speed sensor and directed me to, guess where.. dakota digital. I called them and sure enough they have a sensor that sends a signal to the CPU and has a cable output. The sensor puts out 8000ppm though, so you also have to by an adapter to convert the signal to 4000ppm for the CPU. The sensor was $30 and the adapter was $70 and shipping to Canada was $9, all American dollars of course.
The part numbers are (if anyone is as stupid as me to do this swap) SGI-5 for the adapter (universal speedometer interface) and SEN-01-1 for the sensor (Pulse Generator for GM).
It's going to take 5 days to get to me but the car is in storage so it may be another month before I can install this baby and let you know how it works. I will take a bit of re-wiring but nothing I haven't had to do already.
Anyways Kal, I come on here this morning and there's your reply. I wished I had of checked on Thursday to see if you had of written back, but such is life. Thanks very much for your help eh!
I feel like a kid in a candy store, I love these cars, you can do anything you want to them!

Scamo-2.8

iTrader: (16)

If anyone has any questions about swapping in a 90 v8 into a pre 90 car, pm me and we'll chat.
And thank you again Kal, what can I say but your a genius!

kal

Hey thanks you are too kind Just glad I could help. I'm usually the one asking for help though. Some of the guys on here really know just about everything. Can't even guess as to how much time and money they have saved me. Just glad I could pitch in for once.

cody mcguire

can i get some info on the underdash part?

Scamo-2.8

iTrader: (16)

We can try to help, what info are you looking for?

Dyno Don

iTrader: (7)

What you are trying to do is a very simple fix.
You can retain your cable speedo, just run the brown wire that used to go to the v-6 computer to pin C6 of the '7730 and change the chip to optical instead of magnetic speed (in the constant section of the chip program). Of course this requires custom chip, not sure if you want to go there tho.
HTH

Don>>>

Scamo-2.8

iTrader: (16)

I don't know much about chip burning, what do you suggest?