VSV, vacuum switching valve.
Plenty of discussion on this board - try here for instance:
http://www.toyota-supra.info/forums/...r-answers.html

By the way , site owner, the search functionality is really annoying. Like you can't search for "VSV", because it's too short.
"The following words are either very common, too long, or too short and were not included in your search : vsv"

Really annoying.

Good site though :)

hows it goin there nicnet, ive the same problem as you. (hot wen first started and then cold when driven for a short period) i think i will strip that unit out tomorrow and resolder the joints. how long did it roughly take you to take the unit out??

posibly you got the wrong vacuum line hooked up..

It's a really quick job - about 5 minutes to remove.
Basically the same job as removing the stereo (I've been through a few, so have done this job many times).
Detailed instructions on how to remove it found here:
Supra MkIII - Heater Problem Solving

Nic

that's what i'm thinking jfunez, is that i hooked up some vaccum lines wrong or something.. does that seem a reasonable thing to look for fellas? is it possible i'm not getting heat cause of some mismatched hoses?

hey nicnet, thanks for that information. it was very helpful because guess what, i have heat when i want it. i just resoldered the joints like you said. great job. thanks again. Here's a link to my bebo page if you wana have a look at my supra. have not figured out how to put pictures up on this. Damo Walsh <Walshy2103>

looks nice - great condition (wish my bodywork (white)looked like that).
Is it black, or very dark blue?

Mine originally had Irish plates as well, when I bought it in UK years ago. Changed them now to Finnish ones.
Also had to block out the the front fog lights - some problem with them as it's a right hand drive which is very rare here (one guy genuinely asked me whether they made a mistake in the factory, putting the steering on the wrong side).

Had to spend nearly 3k? to keep it on the road this year (after spending virtually nothing for the last 4 years), but was definately worth it - it's a great drive (especially when the heating works), and still turns heads.

Nic