Ok a few MORE quirky questions about my new XJ

[Roundlytes]

So, I have a good jumpstart on the vibration issue, now I have a few quirky little fixes I need to make........

My heater/ac selector.... It blows piping hot air when I want, and ice cold air when I want, but when I change the selector to the floor, or face position, or mix position it just keeps blowing out the defrost vents....... what the hell is the deal with that fellas? Switch? A air damn stuck or something? (good thing is my windows are ALWAYS clear.... bad thing is my freeking feet were frozen solid for the 2 hours it took to get home from my snowshoeing outting today!!)

Part 2.
My Cruise control.
It turns on, I get the indicator, it engages. It stays at speed until I release the button (meaning I can take my foot off the gas & she keeps cruising) but once I release the button, she decreases in speed........ and it does not seem to slow by means of the vehicle just slows down naturally, it seems to be electronically slowing down... and not just 5 mph and it kicks in, it just keeps losing speed.


Again folks, and I know you all will have something for me, THANK YOU!

 

[Bounty__Hunter]

My heater/ac selector.... It blows piping hot air when I want, and ice cold air when I want, but when I change the selector to the floor, or face position, or mix position it just keeps blowing out the defrost vents....... what the hell is the deal with that fellas? Switch? A air damn stuck or something? (good thing is my windows are ALWAYS clear.... bad thing is my freeking feet were frozen solid for the 2 hours it took to get home from my snowshoeing outting today!!)

This is a vacuum problem, check for a leak or inadequate vacuum to the HVAC controls.

 

[Roundlytes]

This is a vacuum problem, check for a leak or inadequate vacuum to the HVAC controls.

No kidding? Damn, you are good Bounty!! I forget, I know somebody on here used to be a Jeep tech...... was that you?

God I love this site!!

Thanks Bounty, at least I know where to start now!

 

[Bounty__Hunter]

Never an official Tech, don't know who that would be.

Maybe fixing the vacuum problem will help the cruise problem.

 

[Roundlytes]

Never an official Tech, don't know who that would be.

Maybe fixing the vacuum problem will help the cruise problem.

I love this place!!

So after chasing down everything that looked like a vacuum line, and after taking out the battery to chase more, I found my leak.... a completely severed line actually. Must have been busted by the person putting the battery in last time......

So, now I have this split line, and I go to start to chase it. It T's right at the midsection of the passenger side fender, it goes back to the manifold (to the port closest to the firewall) and forward to what seems to be the bumper and terminates on the inside of the bumper...... no, I know, it can't be? Can it?

After taking out the headlight bezel/cornering lamp (which did not too much good) I could not get to where the line goes... must have to take the whole front end apart!

Anyway, sorry to drag on.

So to check to see if that was the actual cause of my heater/CC issue, I went through the whole super glue/electrical/duct tape scenario, which all failed as I have only two hands!

I ended up sliding an electrical shrink tube over the line about 4" on each side of the split, two pieces at the split, hit them with the mini torch and PRESTO, I have heat on the floor.

Last question............

Think that will hold? Or should I anticipate replacing the hose?
I will update on if that took care of the Cruise Control issue, I am showering now and heading out to the highway!

Thanks again Bounty.

 

[mujaman]

i think that vacuum line does terminate into the bumper... there is a small vacuum canister (a round plastic ball basically) mounted inside the bumper that the tube inserts into. don't ask me why...

i had the same problem with my heater vents as well. mine were never permanently stuck... but sometimes they would just go back and forth from the floor/main vents/defrost out of nowhere. as weird as this sounds... it always seemed to mess up (change to the wrong vent) when i was going UPHILL, and then go back to the correct vent once i leveled out or went DOWNHILL. weird huh?

 

[Roundlytes]

i think that vacuum line does terminate into the bumper... there is a small vacuum canister (a round plastic ball basically) mounted inside the bumper that the tube inserts into. don't ask me why...

i had the same problem with my heater vents as well. mine were never permanently stuck... but sometimes they would just go back and forth from the floor/main vents/defrost out of nowhere. as weird as this sounds... it always seemed to mess up (change to the wrong vent) when i was going UPHILL, and then go back to the correct vent once i leveled out or went DOWNHILL. weird huh?

That is weird!?

So my assumption of it terminating inside the bumper could be true then huh?
It did also correct my Cruise Control problem for those who are following this or have the same question in the future...... works like a charm now.

Now its just a time test to see if my quick fix holds!!

 

[jay79cj7]

I think there is a small vacuum tank that is under the front bumper.

 

[Roundlytes]

I think there is a small vacuum tank that is under the front bumper.

Any chance any of you fellas know the best way to access the tank so I can switch the line out? What needs to be removed to get to it??

Thanks again all.....

 

[Bounty__Hunter]

Yes, it's a vacuum canister behind the bumper. Not sure on how to get to it, and my MJ isn't here to look at right now.

 

[XJNick]

Hi,

i think that vacuum line does terminate into the bumper... there is a small vacuum canister (a round plastic ball basically) mounted inside the bumper that the tube inserts into. don't ask me why...

Yep, there is a vacuum reservoir mounted in the passenger side of the front bumper -- the one on my Cherokee was actually quite large and was an ellipsoid in shape.

i had the same problem with my heater vents as well. mine were never permanently stuck... but sometimes they would just go back and forth from the floor/main vents/defrost out of nowhere. as weird as this sounds... it always seemed to mess up (change to the wrong vent) when i was going UPHILL, and then go back to the correct vent once i leveled out or went DOWNHILL. weird huh?

This is the result of a faulty vacuum check valve and makes good sense. When the engine is working hard (such as pushing the vehicle uphill), the amount of vacuum it generates is less (sometimes far less) than usual. There is a check valve installed in the main vacuum line running to the climate controls to prevent the vacuum-actuated dampers from changing position should the engine vacuum supply temporarily become weak or unavailiable. For example, if the damper system is pulled down to 20"Hg and the manifold vacuum drops to 10"Hg while you are going uphill or pulling hard, the dampers are going to move to what ever position 10"Hg will place them in and not neccessarily what you've got them set to. A properly working check valve will prevent this from happening.

Hope that helps
-Nick