open vacuum connection

Hi folks,
my 1990 2.3 convertible was coming out of a shop, where they changed the heater core. Now the heater works fine again, but I stumbled over a vacuum connection in the engine compartment that sucks air, but where no vacuum hose is attached. Is there a hose missing, or only a little "dead-cap"? When I put my finger on the connection, I feel the suction of air, but I feel no other reaction from the engine or whatever by closing or opening this connection with my finger.

Jo
 

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Hey Jo,

I've also got a '90 2.3 Vert and just took a few snaps for you.

Takes off somewhere into the fender!

EDIT: I believe this is actually the line which hooks up to the vacuum reservoir in the fender?
 

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THX a lot for the quick reply. Guess the mechanic has forgotten to put this hose back on. What do you mean with "vacuum reservoir"? The crappy thing on my picture?
 

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Heya,

The picture you've posted is of what's called the 'carbon canister' (an emissions system related part)

The vacuum reservoir is a plastic sphere/orb hidden within the actual cavity between the fender panel and frame.

So hooking it back up may not be the most straight forward endeavour unfortunately ! :(

But I don't think it's exactly disastrous if you wanted to make do without for a moment
 
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just went out to take a look under the hood again:
on my car, the line to the vacuum reservoir is attached on the right outlet instead of the left outlet like it is on yours. But that will make no difference. But we now know, that the other line is missing. On your picture it goes to the right and will end where?
 
It might be worth double checking they're all hooked up in the correct locations again after all this malarkey too!

The hose going off straight to right hooks up to the vacuum tree in the spot highlighted and the other one off the bottom ducks into my firewall.

Hope these help you out :cheers: :D
 

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thanks a lot for the pictures, your help was very good, I appreciate it a lot!

Now I figured out, that the one going into the firewall is missing at my stang. The car guy that changed the heater core pinched it between the grommet and the firewall. Luckily, I have seen a little piece of the hose shining through the hole, grabbed it carefully with a wrench and pulled it more or less carefully out. Hope I didn't loose the other side of the hose, because at first I had to try, which end has to come out. Unfortunately, the hose rubber connector got off the hose and stuck behind the firewall, but what the heck, some Ducktape will do at first hand.
I changed the tubes for the correct location, too.

Now I would like to test, if this hose isn't leaky, but therefore I have to know the function of it. Unfortunately, there probabely is no chance to see where it comes out behind the firewall without dissambling any kind of stuff. Already tried it, but I gave up, after I removed the glove box. Do you know, what it is for and how I could test it?
 
Run the engine for a few mines. The vac canister in the firewall will build up a vaccum reservse. Run the fan. Can you change from defrost to vent easily? If so, then you are getting vaccum to the various vac solenoids in the dash.

Now shut the engine off. Wait 20 second and then switch from vent to defrost. You should hear the solenoids in the dash moving. If you hear nothing, the vaccuum leaked out immediately due to a leak.
 
@Mustang5L5: did it. All Air-outlets are working as they should. Nothing to hear after 20s, only if I turn the switch just seconds after engine off. Do you know, where that vacuum hose is for/goes to after going through the firewall?

figured out myself: it is for the defrost flap. loosen that hose: flap doesn't work, fit that hose, all flaps are working. Don't care that much about the instant gone vacuum after engine stop, or should I?
 
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It’s just a vacuum leak that’s all. Any vaccum leak has the potential to create issues for the engine when air is being drawn in after the MAF.

if the engine runs well and it does hole vac for a few seconds after shutdown, it’s probably tiny and I wouldn’t lose much sleep over.
 
Get out your spray bottle with some "lightly soapy" water in it and start spraying on any area that has to do with the vacuum while the engine is running..