Ok I have an '89 RS w/ 305 TBI, I'm swapping to a 350 TPI (MAP). So my questions are:

Do I need to change the VSS??
What about the ESC? Where is this located?
The MAP sensor should be the same, correct?

Anything thing else that I may have over looked?

 

Yes. The 89 TBI ECM runs off of a 2000 ppm (pulses per mile) signal and the MAP TPI system runs off of 4000 ppm.

You'll need the VSS module from the transmission of the donor car, and the VSS buffer module (which converts the sine-wave signal that the VSS outputs into a square-wave signal that the ECM accepts) from the dash wiring.

ESC needs to be swapped as well. It's located on the drivers side firewall behind or near the relays. It's a flat box with a large flat connecter. Vader's got gobs of pics of it on this forum.

MAP sensor is the same.

 

So, what if I don't have a donor car, can I get one of these modules and buffers at a Junk Yard?

Could I run the car without the correct VSS? This really sucks.