A/C

Just drove this weekend from phoenix to denver to buy an 98 XJ I liked and when I hit the valley here (110 degrees) noticed I have a BIG problem. A/C gets cold, can hear the Fan under the dash workin hard but no air blowin from vents, "whats up with that"?

does it seem to blow ok till you start to work the motor, ie... pulling a hill. mine works fine till i'm working motor. asked a/c guy at shop and he said it is normal. don't know about that, but it does seem to work fine most of time. good luck.

To the OP: If it's only blowing from your defrost vents then you have an vacuum leak

I have the same problem as arkieinaxj. When I start to work the motor it cuts out then blows from the defrost vents. So mine is normal AND I have a vacuum leak?

When motor is under load, vacuum decreases. No vacuum default is defrost vents. Yes, you have a vacuum leak.

When blower fan is blowing hard, and not much air comes out (anywhere), you probably have evaporator freeze-up. Usually there is not much that can be changed to fix this. As far as I know, XJ's do not have a evap temp sensor, although the high pressure sensor is supposed to help avoid the freeze-up. Freon charge can also be manipulated to try to help this.

The main things you can do to minimize freeze-up are: Keep windows closed to not keep letting humid air in and run in MAX or recirc mode for same reason. The evap has to get the moisture out of the air, which is what freezes up on it. Keep the fan on a fairly high level to promote air flow over the evap instead of leaving it on very cold and turning the fan on low. Turn the temp warmer instead of the fan lower. Hope this stuff helps you.

Sounds like the a/c flap door is closed in the box. Either it broke, got disconnected, has a vac leak to the operator, or the cable doesn't work. The actual a/c - compressor, evap, etc is working if you get cold air out somewhere.

The box is buried under the dashboard, you will want a manual to find all the hidden screws and such so that getting there won't destroy all the brittle plastic.Getting to the problem is most of the problem.

NO NO NO NO!!!!! winterbeater is right!!!! If it works at idle, then stops blowing out the vents under load, then you have a vacuum leak or your vacuum canister is unplugged, check it, its under the bumper.

tragiccomic1972 said:

NO NO NO NO!!!!! winterbeater is right!!!! If it works at idle, then stops blowing out the vents under load, then you have a vacuum leak or your vacuum canister is unplugged, check it, its under the bumper.

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x2, and now would be a good time to relocate that vacuum reservoir from behind the bumper into the engine compartment nearer the firewall.

There is yet another possibility that I fixed on my XJ just today. I too had the AC blowing out the defroster under load. My cruise control would also never force a downshift and therefor I would just go slower and slower when climbing a hill on the interstate. The cause was a bad vacuum check valve. The one directly between the intake manifold and the vacuum line that runs to the vacuum resevoir. Under load, the engine was using up the stored vacuum. I replaced the check valve and both problems were completely solved. $4 part at Checkers.

Z do you have a pic of where your talking about? I just cant seem to figure out where your talking about. I have a 91 so I don't know if that makes a difference in your diagram.

"x2, and now would be a good time to relocate that vacuum reservoir from behind the bumper into the engine compartment nearer the firewall."

--- Now thats thinking with your Dipstick Jimmy!!!!

balrog429 said:

Z do you have a pic of where your talking about? I just cant seem to figure out where your talking about. I have a 91 so I don't know if that makes a difference in your diagram.

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Sorry, I don't. And mine's a '96 so who knows, it might be different. Look at the intake manifold. It should have a few vacuum ports connecting to vacuum lines. Locate the vacuum line that goes to the firewall and then runs over to the passenger side towards the Cruise Control and resevoir. On my 4.0, between the port on the intake manifold and the vacuum line, there is a vacuum check valve. It's just a little plastic disc looking thing the diameter of a dime. If you remove it, you should only be able to suck air through it one direction. Otherwise it bad. Mine was bad. After replacing it, my AC and cruise problems were completely fixed.