L82sharkvette

Hey forum, this is my first time back on this site since late 2013. (i forgot my old account info), anyway, i have a bit of confusion about my intake manifold on my '78 Silver Anniversary. That vacuum fitting by my Thermostat housing, what's the reason for it? It doesn't have lines running to it so i'm a bit concerned. Excuse my ignorance about the car, i'm still learning things about it i guess.

Thanks, Gary.

speedreed8

TVS temperature vacuum switch, controlled vacuum to the EGR and tee"d off vacuum to the purge valve on the charcoal cannister. (fuel vapor)..

L82sharkvette

Is it alright to just leave that sitting there, or should it be taken off and plugged?

7t9l82

It's a leavarite leave it right there it won't hurt a thing. But it doesn't really help either.

AboveTheLogic

It it isn't leaking coolant, and it doesn't bother you, then I'd suggest leaving it as-is. If you pull it out and put in a plug and it leaks coolant, you might wish you had just left it alone. Especially if you end up stripping the threads when pulling it out, which happens.

L82sharkvette

Thanks for the information you guys!

bluedawg

Back when alaska had immisions I had to take my vette to the referee station because it had after market aluminum heads, intake and camshaft which caused the Im stations to fail it even with the carb numbers and cards. The only thing I had to do to pass was put the vaccum switch on. It passed all the pipe tests. The point is if you have Im they might consider it original equipment and want it there to pass so if you do take it off, save it.