So after i pulled the windshield washer fluid cap out of my snorkel (man that freed up some extra power!) I was doing some thinking... I pulled the snorkel appart to check and see if the THERMAC valve was working.. specifically to see if it was stuck shut.... nope-- it was the windshield washer fluid cap blocking the air... BUT the THERMAC wasn't working either... but it was open so i didn't really think much of it.

It occured to me that there is nothing connecting the THERMAC system to the car... i.e., it doesn't get power.... So i was just wondering how this system is supposed to work... Does the thermestat in the air cleaner run off a mercury therometer or is something unplugged that shouldn't be??

I'm not really concerned about it because like i say, it's stuck open, but i'd like to know how it's supposed to work

 

It has its own thermostat in it; when the air temp in the snorkel is below some predetermined value, it allows the vacuum that's supposed to be hooked to it to pass to the diaphragm that works the valve, which closes the cold air intake and forces all the air to be drawn through the hose that goes down to the heat stove wrapped around the exhaust manifold. It's for faster warmups, both for better cold-weather driveability and emissions.

 

Not sure if this applies to a thirdgen, but on some GM cars/trucks it's not ran by vacuum--just a thermostat that opens and shuts.

 

If you are running a carb make sure the vacuum line for the Thermac is plugged into the back of the carb. If you want the thermac valve to be open, then pull the vacuum line off the back of the carb and cover the open hole with a slip over plug. Then you won't have to worry about whether it is working or not. It will always be open

 

stick an open element on there and be happy the thermac is restricting some air and why do you want hot air coming from the heat of the exhaust on there?? if its stuck open its always feeding you hot air...just plug the line going into the carb and throw the single snorkel air cleaner in the river and spit on it

 

No, it is if it is stuck closed that you will be force-fed hot air.

Sounds like an LG4. Try and get a dual snorkel cleaner, it will knock a full .25 secs off your ET

There is one on the Temporary Classified board right now for $100.

 

I purchased a dual snorkel air box only to later discover one of the vac motors wasn't functioning. I repaired it--along with the TVS, which was causing the EFE valve to remain open--and suddenly my 'cold-blooded' IROC was another car.

JamesC