[~The Jester~]

Anytime we test something at the track, and have problems, we hit the big "reset" button. Put it back the way it was, and see if it goes away.

Set your TPS voltage (I'm not the guy to help with that, but there are several running around on here that can) and see what that does. If that doesn't fix it, yank the spacer and see if that fixes it.

Sounds to me like ya got yourself a vacuum leak. Good gaskets on BOTH sides of the spacer? Torqued down properly?

This is an easy fix, we did "this" and the car started doing "that". Well, "this" is your problem. It's something you guys did to it when you put that spacer on. Check/set the TPS first.