This here posted by Hailers...

"The thermowax won't extend if there is no water flowing thru the throttle body or the passage in the throttle body is clogged with ???stuff."

Now onto my question... (RotaryRockstars that is!)
When I did the vac-rac/emissions removal a year ago, all the write-ups I read said to just sever the coolant line under the UIM and plug it, because it was too much of a pain to re-install and superfluous. Reason being that the TB never got hot enough to need coolant.

Thus, am I to understand that the coolant hose feeds the thermowax (piston?) and is neccesary for a good idle?
I am desperatly trying to understand the fast idle cam and thermowax system, but am having and extremly hard time. Can I (Healthily?) compensate for my 1500 rpm idle using the Cam screw? I've never touched it because in the FSM is states that unless it's been tampered with (which "no" to my knowledge) it doesn't need to be adjusted.

Thanx!
88 T2

 

The thermowax won't expand if there is no water passing thru it. So its possible that you could have a high idle because it did not expand and shove the fast idle cam off the roll pin to allow the throttle plates to close all the way as they should.

An exception is in the summer in Texas. The under the hood temps/engine temp gets high enough after a while to make the thermowax's piston expand and do the job.

You probably can play with the fast idle screw and make the cam come off the roll pin all the time. *I think so*. Not sure. I might play with one tomorrow and see. Might not if I forget.

Thermowax and fast idle cam...roll pin are best understood if the throttle body is removed and scalding hot water is poured over the thermowax body. For me anyway. Also the pictures in the FSM help a lot.

I already forgot your question............

 

You mean...

"...the TB never got[sic] cold enough to need coolant."


-Ted

 

ohhhh, right... it would be the reverse then... Well that makes sense. I had never actually thought about it, lol. What's funny though is what I said before is the argument I had read. So honestly, I'd bet a lot of people who've done the removal of vacrac are under the same impression I was. That info about the possibility of making your idle high should be added to those threads. I never saw it anywhere...

 

Just do the TB mod..

 

Naaaah. Just put the water hose back on the throttle body where it belongs.

 

^^^ or that too...

 

I want to see if I can do neither of those. I enjoy the ease of low end driving that is said to be lost with the TB mod, that sometimes you get bucking. However also I enjoy being able to remove the UIM so easily w/o that hose there. Beside I mangled it when I removed it, and if I remember correctly it was a crazy shaped molded hose. I don't know where I would find one... I guess mazdatrix has if for $7.00, not bad... Would the S5 hose work? It seems longer so maybe a little bit easier to work with..
If not, I want to just try and adjust the cam screw to see if I can just compensate. I can't tonight I gotta drive her to work. But, tomorrow and update will follow.
Probably with some more questions! sigh...

thx...

 

Then at the very least you have to remove the thermowax assembly, but that causes all kinds of other issues with the secondary throttle plates if I recall correctly.

 

A word to the wise, gents. Don't cap the coolant outlet. It's a ready-made point of failure. Drill it, tap it, and plug it. I've seen one of those rubber caps fail and destroy an engine. By the time he smelled coolant it was too late. These cars (especially the turbo ones) get really hot in that area, and the heat has a tendency to fatigue the rubber very quickly. It's really easy to forget about too cause it's buried under the manifold.

Even if you're out some place and the cap bursts, and you do manage to catch it in time to save the motor; Unless you've really cleaned up your vaccuum hose situation it's almost impossible to replace the cap without at least partially-pulling the UIM.