Confusion reins supreme!!

'87 Camaro
'92 Firebird gauges

AFAIK, '87 700R4 trans.

Where & what is a VSS?
Where & what is a Bufferbox?

The ECM has been removed by a PO at some point.

IDK what I need to do to get speedo to work.

Any help // tips on this Greatly Appreciated!!

 

87 had mechanical cable to instrument cluster VSS there with yellow buffer box feeding vss signal to ECM. Probably don't need any of that now with carb. But, to get 92 speedo to work you need the 4000 pulse per mile input from the correct ECM which you don't have nor do you have the original cluster buffer with cable. You are kinda stuck it appears.

 

To set it up like a Firebird, you need a VSS buffer from 86-92 Firebird except 90-92 TPI or 90-92 Camaro w/ TBI. I think those were typically installed in the dash.

The VSS in some third gens installed in the tailhousing and had a gear driving it, so inside the trans. were speedo gears very similar to a mechanical cable speedo drive.

Alternately, you could use a reluctor wheel and magnetic pick-up type VSS from an '89-up truck. Then you'd need the correct buffer box. The reason this works is the 4004 pulse signal from the buffer box to the speedo works.

Your Where/What questions mean you should search thirdgen more and read some more.

Wiring it - refer to the wiring diagrams for the vehicle you're trying to copy.

 

Don't you just hate it when someone answers a perfectly fine question with search and read?

 

yes,search and read takes hrs without finding the answer at the end.I've done that alot.I've had some issues in this area.Had a person tell me the make GPS gizmose that tell you you MPH and have the extra resorse of getting directions when needed.This dosnt fix the gauge but might keep you from getting a ticket until you get your info and parts collected up.Try radio shack amd such.GOOD LUCK.

 

You're right. Re-wiring a car to correctly operate parts that weren't installed originally nor provisioned for in the wiring should be a thread-start away from a step-by-step manual delivered on a silver platter.

Which begs the question of why you didn't provide him that.

 

I saw the bufferbox wire diagram in another thread, & know where to look for it. { IF whoever did this swap put it in }
Can't do anything til the end of April due to work schedule. I will check the trans to see what's there.

Anyways, yup, I searched threads-- the more I read the more I was confused on the issue.

Dakota Digital said to look at the Cable X.
Autometer said to find out what exactly the trans uses since it is completely possible it has been swapped also.
I looked at Cable X.

When time allows, I will get this sorted.

I DO Appreciate All the input!!

 

BTW--
jmd--

Thanks for the very helpful info!!
Hindsight--- it would have been helpful if the PO I got it from would have told me the gauges don't work etc... etc.... DOH!!!

I was under the impression all I needed to do is paint & go.......

 

Quote:
Originally Posted by utilityguy2
Don't you just hate it when someone answers a perfectly fine question with search and read?

You're right. Re-wiring a car to correctly operate parts that weren't installed originally nor provisioned for in the wiring should be a thread-start away from a step-by-step manual delivered on a silver platter.

Which begs the question of why you didn't provide him that.


Probably because I didn't have one.

mixing electronics stuff is never a good idea. But I hope he gets it done.

 

hey all, i just removed the ecm from my car. my ? is can i still use my buffer box to run my speedo without the ecm? or how will i have to run my speedo? thanks

 

If you have the buffer, Then you are OK as the VSS feeds the buffer then buffer sends to speedo and also sends to ECM. Take out ECM speedo still works. Not sure 92 had buffer depends on tpi or tbi I think.

 

i know that 90-92 tpi had no buffer box, but the tbi cars did

 

sounds like he needs that dakota digital box now

 

it was a tbi car. do will my speedo still work if i unplug all the wires that is in the wires that is going into the ecm harness. im confused. this is a big head ache. thanks for all the help.

 

try it, make sure the vss is for tbi too

 

trace the wire from the speedo, on a tbi i think its tan. then make sure the two vss wires are connected to buffer box (purple and yellow), Then IIRC all you need now is the 12v wire connected to 12 volts .Then just disregard the other wires that used to go to ecm

 

i will see if i can dig u up a tbi vss/buffer box diagram

 

ok,looks like pin F on your buffer box is the one you dont need to use. Pin F is OUT to ECM.

 

I take it you converted to Carb? Why don't you just leave everything alone and drive it? Not hurting anything and if you want to go back or sell it, it's there..

 

i have already started pulling all the wires. i have two wires that are running from the buffer box to the ecm harness and i cant see if i can let them go and still keep my speedo. or would it be easier to convert over to a mechanical speedo. sorry didnt mean to hi jack anyones threads.

 

just pull the wire at pin F at the buffer if your gonna pull any at all,but u dont have an ecm anyway

 

Not a 'jack, topic related, it's all good!...

Did you get it done?

 

Well I got the new motor in and broke in. I still am not near done tho. There is a huge wire harness that does into the drivers side fire wall that I would like to cut down. Most of the wires came from the ECM and such. I just wanna run the basics, lights, horn, relays, turn signals etc. new motor does sound mean can't wait to get it done