1990 wrangler 4 wheel drive vacuum line?

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I have a 1990 Jeep Wrangler who's vacuum lines have been disconnected.
I need help sorting them out as to what goes where. I think I have most
of them connected properly but my 4 wheel drive light is on, but when
you ramp up the rpms it goes out. I just need some help getting the
lines in their proper places so the Wrangler idles rather than
stalling.

Thanks for the help
Jeremy


Re: 1990 wrangler 4 wheel drive vacuum line?
To fix the stalling, there is a black plastic line that goes from the
driver's side of the engine down to the vac switch on the driver's side
of the transfer case. Find the line and plug it, that should get your
engine running correctly. If not, keep working on the vac lines.

To check out the vac operated axle disconnect, hook up the vac line to
the transfer case switch. With the engine running, CAREFULLY pull the
connector to the front axle off the vac motor. The green line should
have a slight vac with the transfer case in 2wd, the yellow line should
have vac in 4wd. If it doesn't switch back and forth, replace the vac
switch on the transfer case, $25 from the dealer. If no vac on either,
you have a bad vac line somewhere.

Your symptoms sound like a cracked vac line or trashed rubber connector
for the line to the switch or vac motor. Pretty common for that vintage
Jeep.

Jeremy wrote:
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Re: 1990 wrangler 4 wheel drive vacuum line?
What engine?

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos:  Non members can still view!
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Jeremy wrote:
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Re: 1990 wrangler 4 wheel drive vacuum line?
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I've got an 87 YJ with a 258 that I did that to once. If I recall, I
accidentally switched 2 vacuum lines 'somewhere near the distributor cap'.

Sorry I don't recall clearer.



Re: 1990 wrangler 4 wheel drive vacuum line?

Jeremy wrote:
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Sorry I forgot to mention its a 6cyl. 4.2L. Automatic.


Re: 1990 wrangler 4 wheel drive vacuum line?
Jeremy wrote:
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Here is a good site for most things to do with the 4.2.

http://home.sprynet.com/~dale02/list.htm

Is the emissions computer still in the loop?  That can mean lots of the
vacuum line stuff is not needed.

The bad idle can be unrelated to the vacuum lines.  That carb is
notorious for getting plugged up idle tubes.  Here is a site on the test
for this and the fix:
http://www.off-road.com/jeep/tech/engine/carter.html

If you have oil blowing into the air filter, that can be another reason
for bad idle with an easy fix.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos:  Non members can still view!
Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
(More Off Road album links at bottom of the view page)

Re: 1990 wrangler 4 wheel drive vacuum line?
Thanks for the site. I looked up the vacuum lines and to the best of my
knowledge hooked them up. Only problem is my set up varies from that on
the site and Im not sure of I hooked up the lines correctly to the
carb. That is the only problem I am having know is the lines from/to
the car. IE the decel valve and I am pretty sure I do not have a pulse
air valve on the drives side. If anyone can help that would be awesome

Thanks Jeremy


Re: 1990 wrangler 4 wheel drive vacuum line?
Thanks for the site. I looked up the vacuum lines and to the best of my

knowledge hooked them up. Only problem is my set up varies from that on

the site and Im not sure of I hooked up the lines correctly to the
carb. That is the only problem I am having now is the lines from/to
the carb. IE the decel valve and I am pretty sure I do not have a pulse

air valve on the drives side. If anyone can help that would be awesome

Thanks Jeremy


Re: 1990 wrangler 4 wheel drive vacuum line?
If you don't have the decel valve or the pulse air system, no worries.
There are a ton of varieties of emissions components according to what
part of the world the Jeep was sold in.

Oh, both pulse air valves if you have them are on the passenger side.
That drawing is just a schematic, not a design.

If the decel valve is what I think it is, it is a factory defective part
that doesn't work.  It was or another one was behind the carb and was
tied into the charcoal canister as well.  The replacement is just a T or
straight fitting to have air flow.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos:  Non members can still view!
Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
(More Off Road album links at bottom of the view page)

Jeremy wrote:
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Re: 1990 wrangler 4 wheel drive vacuum line?
Oh, the straight fitting would be in the pulse air tube, you don't want
that sucking in the back side of the carb or it won't run for crap.

The purge from the canister should also just T into the PCV line behind
the carb with not valve in the way.

Mike

Mike Romain wrote:
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Re: 1990 wrangler 4 wheel drive vacuum line?
Yeah I got that much. The Jeep now wont fire it turns over fine. Also
it kinda sputters when I first turn the key on and or off.


Here are a few pics of my carb hopefully it works...

<a href="http://tinypic.com" target="_blank"><img
src="
http://i10.tinypic.com/30tntwy.jpg" border="0" alt="Image and
video hosting by TinyPic"></a>


Re: 1990 wrangler 4 wheel drive vacuum line?
Yeah I got those hooked up. Just now it turns over but will not fire.


Re: 1990 wrangler 4 wheel drive vacuum line?
Is it flooded out?  They can flood bad enough to need the plugs aired
out.

Is the carb getting gas?  If you look down the throat of the carb and
give the throttle a shot with your hand, you should see two streams of
gas squirting.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos:  Non members can still view!
Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
(More Off Road album links at bottom of the view page)

Jeremy wrote:
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Re: 1990 wrangler 4 wheel drive vacuum line?
Its not flooded and it is getting gas. I'm thinking the distributor
line might be hooked up wrong. That or maybe my TAC vacuum line that
goes to the carb is in the wrong place. I'm trying anything and
everything at this point. It all looks good until I get to the carb. I
think I may have lines in the wrong places.


Re: 1990 wrangler 4 wheel drive vacuum line?
Stock your distributor should be hooked to a bottom plate nipple off the
carb on the right side facing the engine from the front. The nipple
might branch off the brake booster line.

The TAC comes off the back drivers side corner of the carb bottom plate.

Mike

Jeremy wrote:
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Re: 1990 wrangler 4 wheel drive vacuum line?
I have checked and re-checked all vacuum lines they look good. Engine
turns over but will not fire. But every now and then it will fire up
and run fine. If anyone has some more advice that would be greatly
appreciated.


Jeremy


Re: 1990 wrangler 4 wheel drive vacuum line?
     Maybe spin it faster with another battery jumped?
     Coil bypass at solenoid may not be connected or powered.
        God Bless America, Bill O|||||||O
mailto: snipped-for-privacy@aol.com http://www.billhughes.com /

Jeremy wrote:
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Re: 1990 wrangler 4 wheel drive vacuum line?
Dead body ground will cause symptoms like that.  There is supposed to be
a wire mesh strap from the engine head to the firewall.  When this goes
bad, you can get those symptoms.

Bad connection on the starter relay that sits on the firewall at the end
of the small battery cable.  The green wire I believe is the one to
clean.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos:  Non members can still view!
Jan/06 http://www.imagestation.com/album/pictures.html?id=2115147590
(More Off Road album links at bottom of the view page)

Jeremy wrote:
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Re: 1990 wrangler 4 wheel drive vacuum line?
Ok so I checked all of that and cleaned them.
It seems like its getting to much gas and choking its self out. But it
runs for a few minutes slowly dies out and will only start back up
after it has been sitting for a couple of minutes. Git any other ideas
lol.

Thanks
Jeremy


Re: 1990 wrangler 4 wheel drive vacuum line?
Has the catalytic converter been checked to see if it is clogged?


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