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Author Topic: Yet another vacuum line question  (Read 2371 times)

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Online johnbendik

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Yet another vacuum line question
« on: October 11, 2015, 02:45:18 PM »
I apologize in advance for this post, because I know there is a ton of vacuum line info and diagrams here and on the Eaglepedia.  Unfortunately, I can't match the diagrams to my Eagle well enough to figure them out.  So I'm throwing some pictures out here and see if someone can put me out of my misery.

For the record, my Eagle is a 1984 Canadian 258, and the sticker says it is a 'high-altitude' model.  My problem is a very audible vacuum leak that was probably caused by my tugging and pulling on some unrelated components to get to the rear-most valve cover bolt.

I tracked the leak by ear, and found that the sound was coming from a vacuum fitting on my rear of my intake manifold, just inboard from the coolant hose.  It had two outlets; one of them has a hose on it going through the firewall and the other is open.  Putting a finger over the open one confirmed that it was the noisemaker.  Here's a picture of the fitting:


All of the diagrams I've seen show only one outlet on this fitting, so that's the first source of confusion for me.

There is also a partially connected 'Y' fitting flopping around in the general area.  The small line on this fitting goes to the passenger side and then to a tri-color 3-line fitting that I believe is for the 4WD-disconnect crapola.  I don't care about this, because I have done the 'wired transfer case lever' and 'hose clamp on the front axle disconnect' mods to lock my Eagle into full-time FWD.  Here's a picture of the 'Y' fitting:


Also, I found a 2-inch disconnected section of large vacuum tubing just sitting on top of the intake manifold.  I'm guessing that it went on the base of that 'Y' fitting, and connected it to the empty port on the intake manifold fitting.  If that is the case, then where does the other large tube on the 'Y' fitting go to?

Lastly, this is a picture of the 'Christmas tree' of vacuum lines on top of the valve cover.  I don't think it's related to my current problem, but It's always bothered me that some of its connectors are open, so I'm including it:


Any insight as to what those two open fittings should connect to?

Thanks in advance to anyone who has plowed through this post, and any help you can offer will be greatly appreciated.

JB
1984 Eagle Sportwagon
258 - 6 cyl
5-speed !

Offline amcfool1

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Re: Yet another vacuum line question
« Reply #1 on: October 11, 2015, 04:13:19 PM »
hi in picture 3 with the 3 vac switches, the one on the left, (looking from steering wheel, ie drivers side) is the idle speed control. The one in the middle, and on the right, ( Towards pass side) control the pulse air system,which i don't know if you have or not, if not, just plug those two.
picture 1, that is the main vac feed for the whole system. if you are not using it, definitely plug it, I don't see how your car can run well with that open!
picture 2, the big vac line went to the main feed in pic one, you are correct. the small black "hard" vac line was/is the main vac feed to the 4wd vac system, which i gather you don
't need any longer. the open end of the "Y" went to feed some other vac systems, such as the cto, egr, etc, not sure just from that picture. plug it if not using it, or better yet, figure out where it's supposed to go, and connect it properly. there is a good 84-88 vac diagram available in the eaglepedia. just take your time, identify all the parts, and follow the diagram. good luck, gz

Online johnbendik

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Re: Yet another vacuum line question
« Reply #2 on: October 12, 2015, 11:46:47 PM »
Thanks, gz.

Your info about the pulse air system resolve two mysteries: why those ports were open on the 'Christmas Tree', and why the back of my air cleaner looked like this!:


I'm still baffled about the 'Y' fitting.  I disconnected and plugged the small line, since I don't need the vacuum-operated 4WD stuff.  I tried hooking the base of the 'Y' fitting to the intake manifold port, and looking for an open port within range of the 4" hose, but couldn't find anything.  So I pulled the 'Y' fitting off of the intake port and just plugged the port.  This means that the only thing still hooked up to the intake manifold port is the line going through the firewall high on the driver's side.  Other systems on the car that rely on vacuum are obviously working (like the brake boost), so I'm not sure what's going on.  Maybe the line going through the firewall come back into the engine bay somewhere else?  Or there's another source of engine vacuum?  I don't see any other fittings on the intake manifold...

With the posts plugged as I described, the car seems to be running great.

Thanks again for your help.
JB

1984 Eagle Sportwagon
258 - 6 cyl
5-speed !

Offline amcfool1

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Re: Yet another vacuum line question
« Reply #3 on: October 13, 2015, 12:40:58 AM »
yes, there is another source, there should be a brass fitting directly under carburetor.

Offline kevindpm61

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Re: Yet another vacuum line question
« Reply #4 on: October 13, 2015, 06:26:09 AM »
I need to replicate the pulse air hoses for PA inspection. Could you please tell me what diameter the nipples are on the air cleaner?
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Offline eaglebeek

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Re: Yet another vacuum line question
« Reply #5 on: October 13, 2015, 12:44:19 PM »
In your second photo the larger hose with the Y-fitting does a couple of things:
1) The short end fits into a manifold vacuum port. It should be located on the intake manifold underneath the carburetor.
2) The longer end with the valve goes to the PCV valve. The PCV valve fits into the front hole in the valve cover. The valve with the electrical connector that's beside the carburetor can be removed and discarded. Be sure you secure the wires so that they can't fall on the hot exhaust manifold.
3) The hose that appears to be cut off goes to the vapor canister purge. There are 4 fittings on the vapor canister, which is located on the left inner fender just ahead of the spring & shock tower. The purge fitting is the large port immediately beside the raised "tower" on the vapor canister.

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1984 Eagle Wagon, 258, auto, 2.73 gears, daily driver
1983 Eagle Limited Wagon, parts; sold
2000 Jeep Cherokee, 4.0, auto
2007 Hyundai Accent, radical downsize from minivan, wife's car and she loves it!

"The society which scorns excellence in plumbing as a humble activity and tolerates shoddiness in philosophy because it is an exalted activity will have neither good plumbing nor good philosophy: neither its pipes nor its theories will hold water."--John W. Gardner, in "Excellence: Can We Be Equal and Excellent Too?" (1961)
 
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Online johnbendik

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Re: Yet another vacuum line question
« Reply #6 on: October 13, 2015, 01:39:14 PM »
kevindpm61,

The outside diameter of the nipples are 3/4 inch, with a bit of a raised lip for hose retention.  I ended up removing my 'closed loop' hose and using wine bottle corks to seal the air cleaner holes.  It's a much classier look...

Can't believe PA requires compliance on this stuff with a 30 year old car.

JB
1984 Eagle Sportwagon
258 - 6 cyl
5-speed !

Offline eaglebeek

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Re: Yet another vacuum line question
« Reply #7 on: October 13, 2015, 01:52:14 PM »

Can't believe PA requires compliance on this stuff with a 30 year old car.

JB

Believe it. Colorado does also. :eagle:
1984 Eagle Wagon, 258, auto, 2.73 gears, daily driver
1983 Eagle Limited Wagon, parts; sold
2000 Jeep Cherokee, 4.0, auto
2007 Hyundai Accent, radical downsize from minivan, wife's car and she loves it!

"The society which scorns excellence in plumbing as a humble activity and tolerates shoddiness in philosophy because it is an exalted activity will have neither good plumbing nor good philosophy: neither its pipes nor its theories will hold water."--John W. Gardner, in "Excellence: Can We Be Equal and Excellent Too?" (1961)
 
Air-conditioning is so cool!

Offline Draekon

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Re: Yet another vacuum line question
« Reply #8 on: October 13, 2015, 03:06:43 PM »

Can't believe PA requires compliance on this stuff with a 30 year old car.

JB

Believe it. Colorado does also. :eagle:

I have simplified the system a bit on my '81 and have gotten through Colorado emissions just fine. All they seem to care about is the EGR and the AIR system

Offline kevindpm61

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Re: Yet another vacuum line question
« Reply #9 on: October 13, 2015, 03:30:09 PM »
PA requires a visual inspection of emission components. They don't check individual components for function but they need to be there. This car has been converted to the Weber carb and it runs great. I'm sure that it will pass emissions testing.I just need to make the engine compartment look  stock by putting the original emissions components back.
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Offline macdude443

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Re: Yet another vacuum line question
« Reply #10 on: October 13, 2015, 04:09:33 PM »
I live in PA and have passed emissions multiple times with the Pulse Air removed.  However, I replaced the catalytic converter with a version that does not have the air tube connection, so I eliminated the plumbing.  If you don't have ten things hanging there disconnect it won't look as though anything was tampered with.  I would suggest at least a charcoal canister (that actually works, and can be made to work with the Weber most likely), a PCV valve and an EGR valve.  With those in place and the age of the car, I would think most shops would figure it's intact.
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1986 Eagle Wagon

Offline kevindpm61

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Re: Yet another vacuum line question
« Reply #11 on: October 14, 2015, 08:22:45 AM »
That's pretty much what I intend to do macdude. I bought a catalytic converter without the tube and plan on working on the exhaust system this weekend. The EGR valve is present and I'll mount the charcoal canister. I'll worry about the pulse air if they flag me during inspection.
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Offline macdude443

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Re: Yet another vacuum line question
« Reply #12 on: October 14, 2015, 10:06:31 AM »
That's pretty much what I intend to do macdude. I bought a catalytic converter without the tube and plan on working on the exhaust system this weekend. The EGR valve is present and I'll mount the charcoal canister. I'll worry about the pulse air if they flag me during inspection.

Sounds like a plan.  I have some bad canisters if you would need one.
1982 Eagle SX/4
1986 Eagle Wagon

Offline Nightpath

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Re: Yet another vacuum line question
« Reply #13 on: October 14, 2015, 01:14:22 PM »
Just loop them back into eachother, as long as the inspector doesn't see an open line they won't argue. Most of the mechanics these days can't even tell you what a carb is.

Offline kevindpm61

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Re: Yet another vacuum line question
« Reply #14 on: October 15, 2015, 08:33:30 AM »
Thanks for the info nightpath and macdude. It looks like I've tracked down an air cleaner and I found a charcoal canister at the junk yard last Sat.
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Offline carnuck

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Re: Yet another vacuum line question
« Reply #15 on: November 01, 2015, 01:20:36 PM »
Just one thing. If you replace your cat and aren't running an AIR pump, make SURE it's a non-aerobic cat from a fuel injected Jeep XJ or something. Otherwise you will lose power in short order and the emissions will be through the roof!
Replace the aircleaner with one that A: doesn't have the pulse air ports sticking out, and B: doesn't have the shut down flap that's supposed to close after you turn the car off. They tend to fail after 20+ years and close while driving, causing single digit fuel economy and running problems.
AMC/Jeep gauges are for amusement only. Any correlation between them and reality is purely coincidental!

 

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