73 - Where do these 'things' go?
 

Hi All (again!). The ball valves for the heater core lines went in yesterday and there's no more warm air seeping in anymore. What a relief!

I've got a couple more mystery lines left in order to finish up this 73 Roadster and I have no clue where they go.

1) From my vapor canister, I have 3 lines coming out. The largest diameter line comes out and loops up to the fender wall and just ends and is not plugged. Is it supposed to be an open line? If not, where should it go? (By the way, while tracing the open line, I found that the vapor canister lid wasn't even attached.)

2) From my firewall right behind the dist. cap I have 2 lines coming through the firewall at a single port. The top one loops right back to under the windshield and goes down the passenger side and (I'm guessing) is OK. The lower one goes towards the driver side and ends with the vacuum line plugged with a stick crammed in it. I attached a link to a pic of the line in question and I drew a little circle around the line that's not attached. Where should this line go?

http://www.thestarkeys.org/vette/vac-line.jpg

3) I have a mystery orange wire coming from a harness on the passenger side right up the exhaust manifold and it capped off. It comes across with just a black wire and the black one links up with another harness. In the pic, the orange wire is laying on top of the silver relay (you can see the ball valves I put in the pic!). Any ideas?

http://www.thestarkeys.org/vette/orange.jpg

4) At the rear of the intake manifold, there is a stem that comes off with two connectors. The bottom one is used but the top one is just sealed off. I circled it in the pic as well. Any ideas?

http://www.thestarkeys.org/vette/mani-stem.jpg

Thanks!!!!

Picture # 1 is the vacuum line to the original heater control valve that you eliminated with the ball valves.


# 2, mystery wire is just that, a mystery. A P.O. Probably hooked up a 12v. lead for something like an electric choke or fuel pump. Is the wire switched or is it hot all the time? It could have also been part of an aftermarket alarm system.

# 3 vacuum tee, fuggedaboudit, it ain't no thing. Just a capped off vacuum port. If you ever need to put a vacuum gauge on the engine this is a great "test" port.

My 2 cents worth, I hope that helps!

I almost forgot the vapor canister. They were used to collect gas vapor, condense it and send it back to the gas tank. If I remember right, one line goes to the carb, one to the tank and one just sucks air.

Heater Control Valve
 

Wow! Thanks for the info. I was expecting to spend my day re-connecting these lines. Now, I've got nothing to do today -- except drive!!!

Heater Control Valve: I put the ball valves to temporarily turn off the hot water to the core, but after the summer, I'll let the water flow again. Doesn't this vac line get T'd off to another line somewhere? I'd like to have it correctly connected. And, I have a hissing sound in the dash down near the temp controls and am hoping that it's because this line isn't connected. I get the hiss when I'm in any setting other than heater.

I believe the hissing sound is the vacuum port on the HVAC control that would normally port vacuum to the heater water valve. Need to plug that port.

The canister collects gas vapor from the tank and maybe the carb (don't remember on carb). So the big line I believe goes to the tank, one of the small lines is the vacuum signal line to open the valve in top of the cannister and allow the third line which is connected to the carb or intake, maybe to a tee at the PCV and pulls the vapor out of the charcoal cannister. If the lid is not attached, then it should be reattached w/ epoxy or RTV. If not using it, then all lines should be plugged and a vented gas cap should be used.

On mine, one line goes to the gas tank, one goes to the manifold and the third (wide diameter hose) goes nowhere and it's not plugged. Where should it go?

Any idea where the hose coming from the firewall gets T'd off to?
http://www.thestarkeys.org/vette/vac-line.jpg

Just checked mine. One big line goes down to a steel line that goes to the tank. The small line goes to the carb. Since my engine is on a stand right now, not sure where but the AIM probably shows or maybe the emissions decal. The other big line tees into the PCV line.

Not sure about the firewall line.

Thanks Shark. Looks like I have 2/3 correct. I have 1 line to the carb and the other to the tank. Are you able to take a pic of the 3rd line going to the PCV? If so, can you snap one for me so I can see? Also, when you get your car back, can you snap a pic of that firewall line too? I'm having a heck of a time fiding out where that one goes. Thanks.

I'll have to see if I can find the rest of the PCV line. Will check for the firewall line. Should be easy w/ the engine out. :)

Thanks!!! And why is the engine out???

Couple of reasons, coolant in the oil and really bad cross fire at 4,000 rpm and up. Found two microcracks in between the lifters on #5 & #7. The back lobes on the cam were starting to go Tango Uniform. I've got it rebuilt now w/ LT-1 pistons and a roller cam. CR w/b ~ 10:1. Currently rebuilding front suspension and PS.

Well just checked and can't find the rest of my PCV hoses but almost certain that the hose coming from the cannister went to the same hose as the PCV line. The hose you have hilited on mine goes to a tee which goes to a 2 line check valve which then goes to a vacuum source.

MikeC3, thanks again for the part #'s, got the correct stuff today and will try to install it tomorrow.
On my 74 vapor canister I can only see 2 lines, one goes back to the tank and the other "T"'s into the PCV line. Just looked at MidAmericas website none of the ones they show look like mine and I think the third port of yours is just a vent. PG.

The small vacuum hose going to his cannister is what opens the valve that allows the hose going to the PCV tee to suck the vapors out of the cannister.

My third canister line is a larger line and not connected to anything and not plugged. One line definitely goes to the gas tank and the other to the carb. I've been looking at tons of pics online trying to see something T'd into the PCV line and I've never seen one.

I think that other firewall line goes to vaccum. As I was looking through those misc pics online, I found one that I can kind of see that line and it looks like it T's into a vacuum line. Right now, mine is not attached, but a closed line. From other responses, it sounds like it goes to the heater control, but I'm assuming that end of it is connected correctly. I wanted to know where it gets T'd in the engine compartment, and I'm now guessing that it needs to be T'd into a vacuum line.

Thanks!