I have been trying to locate the yellow buffer box to make my speedo work on my car and have been unable to find it. My car was originally a 305 TBI and I was under the impression that all 90 and up Camaros had this buffer box. I can find no signs of the wiring for the box either. Is it possible my car does not have this? The box should be located on the passenger side of the car, where the computer is, right? I

 

the VSS is 4004 pulse per mile, the ECM takes a 2002 pulse per mile, yes you have one. Follow the wiring from the VSS under-car and find it that way. Or, find the pin on the ECM for VSS-in and find it that way.

 

The "VSS Buffer" is under the dash at knee level, just above the large kick panel that covers the under side of the passenger side dash...It is a small, white box with a connector. It is not really by the ECM, but over to the left a bit...

 

This is what the one on my 86 Trans Am looks like,


Mine was located right behind the flat part of the dash on the pass side where the dash pad is.

I am not too familiar with TBI, but you may not have a buffer box. I believe the 90-92 Speed Density TPI cars had the buffer built into the ECM. Your TBI ecm may be hte same.