There is a connection that fits over these two vac lines on the efe tvs ( efe tvs that sits in the thermostat). i cracked the top one and am not sure wether it means much or not. Herd it was some thing for emmisions.

(1985 Iroc-Z H.O. 5.0 4bbl Rochestor)

 

Yeah everybody "hears" at one point or another, that EVERY THING under the hood that has a wire or vacuum line going to it, is for "emissions", usually from some hack, and usually followed closely by "I just rip all that s*** out and 'clean up the engine bay' ". Then the hack can't seem to figure out why their car overheats, won't pass inspection, gets terrible gas mileage, has mystery driveability problems, and so on... about half of the posts on this forum.

Be smarter than .... those people.

It's the thing that controls the little valve in the outlet of the right exh manifold, that when closed, directs the R exhaust to cross over the top of the motor, under the carb, and then to the left manifold. It's for faster warm-ups in cold weather.

Repair or replace whatever is cracked. It's cheeep and might save you some form of grief someday.

 

Of course you could end up like me that was driving 1000 miles and the TVS started choking the exhaust off on the hiway. I feel this is one emissions device that everyone could live without. It chokes the exhaust until it detects the water neck heating up and then it relaxes, lasts all of five minutes. I suffered a cracked manifold and lost a cam lobe because of that. It's a wonder it didn't cause more damage than it did.

 

can i see a picture of it?