vss in pre 90 TBI

[bp71k5]

One more question on my TBI swap. I forgot to buy a vss and can get one from painless. My truck is a 71, so I'm sure there's not one in there now.

A couple of ck5 posts mention that the vss isn't connected to anything but the speedo from 89 and older. My harness and ECM is from an 89 Blazer. (4x4High stuff).

I have a manual tranny so I don't need the VSS to control the TCC. So if the ECM is setup for VSS, is it even worth adding in my case? I don't mind spending the money on it as long as it actually does something.

 

[4X4HIGH]

VSS helps control TCC (if auto trans) it also lets the ECM know that the vehicle is either stationary or moving to help control IAC function, It also lets the ECM know how fast you're going to help calculate and adjust fuel and timing curves.

 

[bp71k5]

Well then, I just added it to hopefully my last parts order from Jegs. Thanks!