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A/C cuts out when I accelerate?????

G

GGR

NAXJA Forum User
Location
SACTO
For some strange reason my a/c now cuts out when im on the gas. I don't recall this happening before???
I did recently change out the exhaust manifold, could I have left something disconnected?
Has anyone gone through this before?

Thanks
 
You most likely have a leak in your vacuum lines. Mine usually occur near the battery because of the acid leaking out and eating lines. Cut the offending line off and slip some rubber tubing over it and you should be good to go.
Ben
 
My jeep XJ doesnt have air but in my other 3 cars(saturn, Nissan Quest and a 99 WJ)- when I floor it they all cut off unitl I let off... (not the fans... just the a/c system) I think it is the car system knowing that you are flooring it and giving you all the power it has... the a/c draws a lot of power out of your engine...

I think it's supposed to do that... Dont floor it if its hot out...

ken
 
IMORTL said:
when I floor it they all cut off unitl I let off... (not the fans... just the a/c system) I think it is the car system knowing that you are flooring it and giving you all the power it has... the a/c draws a lot of power out of your engine...

I think it's supposed to do that... Dont floor it if its hot out...

ken
Click to expand...
x2
 
We need to know a little bit more information. By you saying it "cuts off", are you meaning the fan? As in, NO air comes out of the vents, regardless of temp? Or are you saying that you floor it, the fan stays the same, but the air goes warm?

Typically, if you FLOOR any car of late, the computer in the car knows that "Hey, I need all the power I can get, lemme disconnect the AC compressor". To put it in lamens terms (BTW, I LOVE my spelling).

Give us a few more clues, we might be able to help.

James
 
My truck is a 91

I do not have cycling at idle, as a matter of fact the system works best at idle now all of a sudden.
It just seems weird, that while im driving, I press the gas down(but not hard enought to downshift the tranny) and I can feel th a/c stop blowing. when I let off the gas the whole system rushes back and works REALLY good.
It's just weird to me.




Thanks for the replys.
 
Every time I go through this with my 85 XJ i've left off or knocked off the vacuum connection under the hood that goes to the climate controls. Went through it again a couple of days ago and was going nuts until I finally checked the vacuum canister and found the check valve had failed. The vacuum setup on your 91 will be different but probably worth a look.
 
GGR said:
I just loose it in the vents.
Click to expand...

Thats a vacum leak, the vent door in the heater/air box is vac controlled. When you have a vac problem and vac drops it defaults to the defroster position and floor. Like mentioned check under the battery, battery splooge eats the hoses.
 
I agree with Rich. It is a vacuum issue. I have in my XJ and had it in my 97 ZJ. Check your vacuum lines and check valve. If the problem is with the lines or valve, it will default to defrost position.
 
Okay I 've ran thorough all of the lines and I don't see or feel any loose or craked or missing. Can it be the check valve? Is the check valve located on the pass side under the hood, behind the battery? I saw something that my vac line went into (thru) and it had a electrical connector on it, Should I replace this?
I really wanna figure this out as it's gettin a little warm here in Sacramento

Thanks guys.
 
It's a vacuum leak, no arguing that...

Check the vacuum bottle on the right side of the front bumper, if that's broke there is your problem. They are cheap from the dealer (not sure if you can get them anywhere else), I would recomend relocating it, I put mine under the hood.

Get a good vacuum pump to check the lines and bottle. If you have cruise control you'll have the large egg shaped bottle, this is how it should work:

Right Side___|___Left Side
o____________|___________o - Small Hole
 O____________|___________O - Large Hole
Each side works independatly. Just block off the small hole well and apply vacuum to the large hole. It should hold that vacuum indefinately. Do this for both sides.

The non cruise control (baseball shaped) bottle should work the same way although it will only have two holes instead of four.

Sequoia
 
Last edited:
Well Im down to do what ever it takes, The problem is I don't know what to do. I can get the vacuum tester from Auto Zone, but I don't know the first thing about testing the system. Any advise on that would be greatly welcome.

Thanks again guys.
 
All you gotta do is plug up the small hole, insert the tube from the vacuum gun into the big hole, and pump the handle. Watch the vacuum gauge, bring it up to about 15 lbs and stop, now make sure it holds that pressure.

Where in CA are you?
 
Thanks guys for all the replies I did find out what the problem was.
I guess when I was doing some work under the hood I crimped a vac hose that connects to the intake manifold and runs parallel with a larger diameter tube that connects to the stock air box and continues up the drivers side fender. (sorry I don't know what it's called)

Anyway I was doing a cheapo air intake mod tonite when I re-examined all of the vac lines and found the bad line, so I replaced it, and no more problems.


Thanks again all!!!!
 
just a note on hard acceleration the compressor will cut out. it allows the engine to get the extra getty up it might need. but will not affect the vents it'll just get warm fer a second.
 
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