New (to me) 1988 XJ Limited and a question

Yes, we're now the proud owners of yet another XJ. This one is also a 1988 XJ Limited (Red), and has half the miles (175,000) of our original '88 XJ Limited (Black). My wife will drive this one and we'll be keeping the 91 XJ ("plain-Jane-model) - - Blue) as a back-up velicle for awhile. The new '88 is in nice condition but it has a few issues I'm working on.

I have searched some in the archives for help with my questions and I know it's there but I just wasn't finding it.

This 88 had a right-front hit that is now repaired. I looked-over the vacume bottle (behind the right end of the front bumper) and could not "see" any damage . . . That's about as far as I have gotten so far. I do recall about checking for vacume leaks including under the battery tray. What the problem is: the heater, blower and a/c all work fine, except, the heat and the a/c come out (primarily) just from the defrost vents and the under dash vents . . . virtually nothing exits from the vents located in the face of the dash. Also, the Cruise does not work ('presently operating on the assumption this is not related). I'm thinking that vacume shitch that's located in the center of the dash . . . I think you either access it by removing the radio and/or the lower section of the dash

Please just help me with my recollection re these items as I proceed to further check into this problem.

Thanks! Don

At what position on the HVAC switch do you get air coming out the vent below the switch panel?
Normally, with it on max a/c, and on heat (I believe) you should get something. If not, it could be as simple as a blockage (read squirrells nest) or the linkage is disconnected. A similar thing happened to my 85' XJ.
As far as the cruise is concerned, I'm not sure. If you open the hood, right behind and up from the valve cover is a canister with hoses going into it. If I'm not mistaken, that is the cruise control module. I am lacking my c/c also, so if you fix it, let me know.

88woody said:

At what position on the HVAC switch do you get air coming out the vent below the switch panel?

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I don't get anything coming out of there. Thanks for the suggestions, though . . . I'll add that to my check-it-out-list. Don

Both the heater controls and the cruise rely on vacuum for operation. When vacuum fails, the default setting for heat/air is the top-of-dash defroster outlets.

It sounds like you have a vacuum leak, and if the right front was whacked the "blimp" is certainly on the list of suspects.

If you cruise does not work and the air only blows out of defrost then I'd say you have a vacuum leak.

Is this 88 XJ a 2wd or 4wd version? If it is a 4wd and it has the NP 231 transftercase then you should have a "part time" light when you pull it into 4 hi from 2 hi. If you don' t have that light then you do have some vacuum repairs to make.

You will need to go to the dealer and buy some stuff. There is shift motor on the front axle, it is located directly under the oil filter. Every time you change oil you drop some oil on the connection. Over time the connection does not hold and the shift motor will not engage. If you have a full time transfercase then you won't have this harness. It a $10 part at the dealer, about 1 ft long.

Also replace the CCV harness systems under the hood. In addition to the large hose from the valve cover to the air cleaner you get all these little vacuum hoses for the air cleaner, EGR, and fuel pressure regulator. Also the owner' manual says to change the CCV stuff every 50,000 miles so it prob overdue.

Changing all that will fix vacuum leaks. My XJ idled better once I change all that CCV harness. I do not recall where the cruise control gets it's vacuum but the CCV system prob supplies it.

If it was in an accident then you never know if you have a bad reservoir or a bad hose. You may need to buy one of the mity-vac at the store and start checking things out.

Thanks, Eagle! Can you believe it . . . I've never had to replace one of the "blimps" (I referred-to as vacume bottle) . . . . if I do need one, are they available after market? If not, any idea re "stealership" price range for one? Thanks again! Don

also check the vacuum lines under the battery tray that lead to the vacuum ball. new one from the dealer should be around $25, at least thats what it cost me for a new one for a blazer.

Thanks to all . . . I'll print this out and be doing further checking as I work to get this into top shape for my wife. Martin, it IS a 4x4 and the front axle engages and disengages properly . . . no problems there. Personally, I've seen so few 2 wd XJ's that I never even thought to mention that . . . all three of mine are 4x4's ......................... interestingly, last winter, I was following an XJ that had it's cable chains mounted on the rear. I had mine on the front (where I think most folks w/a 4x4 mount them, if you're only chaining-up one end) . . . well, after I passed him, I happened to notice (in my rear-view mirror) "no front punkin!" So, I gave him one of those quiet appologies and went on my way . . . .

I would take the xj down to a good parts store that has a good selection of vac hoses and start replacing them one by one with all new. Age is the reason, otherwise you will be constantly chasing down leaks. The reason to do it there is so you get the correct sizes and fittings so pick a shop with a really good selection. Heck, take a lunch I did our YJ the hard way, now I have a lifetime supply of odd thermoid hoses that nobody uses since eagle had his hupmobile..
I would also consider moving that blimp, or a new one, to the inside and eliminate the battery spluge eating the hose under there. You can make them yourself with a coffee can too, I've seen that done before though it does take patience to get the coffee out first...

Once again, THANKS for all the excellent input . . . . I found two vacume hoses going to the blimp, right where they pass through the radiator support, that had apparently been sheared-off in the crash.........................'repaired those and now the blower blows through the dash vents and the cruise control also works. Quick and simple!

RichP said:

... now I have a lifetime supply of odd thermoid hoses that nobody uses since eagle had his hupmobile...

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HUDSON

Not Hupmobile. :sure:

Don Becker said:

Thanks, Eagle! Can you believe it . . . I've never had to replace one of the "blimps" (I referred-to as vacume bottle) . . . . if I do need one, are they available after market? If not, any idea re "stealership" price range for one? Thanks again! Don

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At " Dick " Hannah ( there is a reason they call him DICK ) I got mine in 24hrs for only $14.00 . I thought that was a good deal. Have a 91 though which is different than yours but it gives you an idea.

red91inWA a.k.a. scott f. said:

At " Dick " Hannah ( there is a reason they call him DICK ) I got mine in 24hrs for only $14.00 . I thought that was a good deal. Have a 91 though which is different than yours but it gives you an idea.

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Thanks

Round here I just called to have a blimp ordered and they charge under $17 bucks. Not bad, until I have to head down to the local vac shop and replace all them dang hoses.