AC/Ventilation Problem

jjasper · Jul 30, 2005

I have an 88 XJ that develope this problem suddenly.No matter what the setting of the AC/Heater,air will only blow out of the defroster.I checked the vacuum at the manifold and had about 16''.Do the cannisters go bad?How do you check them? I haven't found any hose leaks.
Any help will appreciated. Thanks

jjasper

RichP · Jul 30, 2005

An 88 with original vac hoses and no leaks, hmmm, check under the battery tray to the vac line that runs out to the softball sized vac cannister behind the passenger side bumper. Battery splooge usually eats them up, then use a spray can of PB, wd40, carb cleaner and start spraying vac lines while the engine is running, as soon as you hear an idle change, up or down you found a crack, broken or damaged hose.

slowrider · Jul 30, 2005

I had the same problem on my 87 MJ and found that some previous owner driven a screw through the vaccume cannister. Replacing it helped at idle but after replacing the cannister and all the leaks I could find I still have the problem under load so it's not easy to find. Keep looking at the vaccume system.

slowrider · Jul 30, 2005

slowrider said:
I had the same problem on my 87 MJ and found that some previous owner driven a screw through the vaccume cannister. Replacing it helped at idle but after replacing the cannister and all the leaks I could find I still have the problem under load so it's not easy to find. Keep looking at the vaccume system.[/QUOTE
One place to check for a vacuume leak that many miss is the ventilation control in the dash. When I pulled my dash apart looking for leaks I found that vacuume valve manifold in the dash melted and full of holes.

AC/Ventilation Problem

jjasper

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RichP

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slowrider

NAXJA Forum User

slowrider

NAXJA Forum User

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