I was checking over the various vacuum lines on my 73 Dart, and although I've carefully examined the engine manual, I've run into a problem. Next to the OSAC Valve on the firewall is what appears to be a Temperature Control Valve. It has two nipples on it. The top one is connected to the Vacuum Amplifier, but the bottom nipple isn't connected to anything. Should there be anything on that nipple, or should it be blocked off. It looks like if I leave it as it is, there would be a vacuum leak at that point. Any ideas?

i'm not sure but i think it's a osac vavle for the distributer. the line on top goes to the carb and the one on the bottom goes to the distributer.

As I indicated in my original post, I've already identified the OSAC. The part is in addition to the OSAC and sits on the firewall immediately to the right of the OSAC. Thanks for trying though.

Where's our resident emissions control expert when you need him??!

Hang in there, I think I hear him coming...

D/W

_________________

If it ain't broke, fix it!

Did I hear someone calling my name?
Here I am!

Ummm.... 1973 emisions..... Let's see, temperature control valve on firewall.... two nipples? OH, yes, I see two nipples. Ah ha!! One is connected to the hose to the vac amplifier. The other one is supposed to have a filter on it. I can't make out which nipple is which just now. It is common for those foam filters to get rotten and turn to dust. The other place you find those filters is on one nipple of the vacuum solenoids too.
Anyone know where to get new filters like that?
See picture.........

Yep, what Craig said. This guy's job is to make or break the EGR vacuum circuit so that there's no EGR below a certain ambient temperature. This was changed for '74 to a CCEGR (Coolant Controlled EGR) system.

Craig: Thank you! Question answered. Now comes the embarrassing part...I now remember removing that foam piece while disconnecting hoses, preparing to remove valve cover to set valves. You guessed it...I through the damn thing away thinking it was just junk in the bottom of my work tray. Oh well, I'll find something to take its place. This site rocks. Grandson got his car back today from the paint shop. He has been OVERHAULED and his ride has been pimped. Its a 73 4-door, originally painted B-5 blue. We had the hood, top and trunk painted B-5 and the rest of the car done in silver. Damn thing looks good...