ok ive looked and looked and cant find the exact into i need. I have a 91 .bird that had 3.1 multiport. i put a 77 350 in it with a 700r4 from a s10 i was wondering .... i want to get rid of all the computer stuff. i was wonder ing if anyone knows of a way to bypass the ecm to make the speedo work.. if this is not possible then i have no idea how to get it to work with it. all the wires are plugged in . the ss may be bad , I know that could be one thing. but what i really want to know is if i can bypass the ecm. and still have a functional speedo. what exactly does the ecm do to make the speedo work? i am so sick of not having a speedo. and ive been through all the wiring diagrams and i dont want to start cuttin stuff that wont end up workin anyway. also if i do need the ecm what are the bare minimum wires i need to make this work witch wires power the ecm and do i need them. all the grounds are still grounded. if any one can help it would be great

 

ECM has no connection to the speedo in a Camaro - wouldn't think it would in a 'Bird either - even with a digital dash I wouldn't think there's be any ECM connection. Speedo should still work, as well as all other guages, without the ECM in place.

 

Camaronewbie, stop guessing the wiring. 90-92 camaros got electric speedos. Not every car will magically be like yours and work the first time with your randomly chop stuff out and hope for the best

Aremy10, your 3.1 V6 was wired the same as a TPI, so the old VSS signal went directly to the ECM and was decoded into the 4000ppm signal correct for your speedo. You need to install a small buffer box to handle this task since your ECm will no longer be there to do it. Find a buffer box from a mid 80's-90s truck, or 89- firebird and grab the connectors. The box can be yellow or white and is behind the lower trim panel on the Fbody dash

Wire the VSS wires (ppl and yel) to the box direct, hook pin H (pink) to 12v IGN, pin A (black) to ground, pin C (brn or grn) to the speedo wire (C207 pin D gray), pin E (red) to cruise module if retained (C209 pin A red) and leave pin F (brn) disconnected

Diagram if you get stuck
http://www.austinthirdgen.org/mkport...SS_V8_vinE.jpg

Buffer box looks like this



If the S10 trans doesnt have an electric VSS, you will need a cable to electric adapter along with the buffer box. Easier method is to use the tailhousing from your old V6 trans and VSS with gears. 4L60 trans parts interchange freely with 700R4 parts along with a good many 4L60E parts

 

thanks for that. i still have the ecm in the car but ive been cuttin stuff out that i no longer need like sensors and stuff like that. i am gonna look into finding a buffer. cause like i said i dont want the ecm in there anymore. im trying to clean all that unesed wire crap out of there. thanks for the info

 

and if i do keep the ecm in the car could i remove everything goin to it escept the ss wires and the gauge wire. witch ones would i have to keep connected to the ecm for it to work the speedo

 

It needs to power up still, so the 12v battery, 12v IGN and all the related grounds need to be there still. Easiest method is with a buffer box

 

the buffer box does sound much easier
thanks alot

 

Old thread, relevant post.....

Once again - Thanx Pocket for the clearly described instructions and detailed information !

I do have a question however; Your post describes using the original 90-92 style Tranny VSS along with a yellow buffer box leading directly to the cluster. What about using an "early" 84-89 style Electric VSS, like this one:



IIRC they are both 4000 Pulse sending units and it seems like I can find the 84-89 style much easier these days.

Is the early VSS a "direct swap" (when correct plug is used) with the 90-92 VSS ?