I have a stock 1985 Corolla gt-s and below 4500 rpm the engine is not reving like it used to before being in storage. I know the tvis opens the butterflies @ 4200 +/-.
The link for tvis in faq isn't working, so does any one have any advice on cleaning, repair, and testing?

To test you can unplug the wiring connector from the TVIS this should keep the TVIS plates fully open all of the time.

Yup, it acts exactly the same with it unplugged. I need to pull it and test the diaphragm.

Get some Seafoam (or Motul if you're a baller) and draw it through the throttle body. If your TVIS butterflies are sticking, this should help free them up without having to take anything apart.

Also, Jondee had some good advice about checking the vacuum lines. Check your water pump post.