VFQuake

It currently has the I6 4.0, with 230k on it. Does this thing still have some life left in it, if it's currently running fine with no problems? What should I focus on when I get it? (mechanically speaking).

Here's the ad for it: http://indianapolis.craigslist.org/cto/3844888139.html

djb383

What does the coolant look like? Hopefully not rusty/nasty. Pass if it does. Clean and green can be a indicator of good/proper maintenance. Obviously rusty/nasty is a sign of owner neglect.

VFQuake

Sorry, I meant specifically with a Cherokee, I fully plan on doing a full tuneup (oil, plugs, wires, filter, flushing coolant and recapping, checking hoses etc) Depending on how the timing belt looks, I may replace that as well, though that is not something I'm looking forward to. I guess I assumed there were probably certain "cherokee" things that are common, and that one may want to look out for. It's my first Cherokee.

Radi

No timing belt, the 4.0 uses a chain.

230K isnt' a big deal on a reasonably well maintained XJ. On a poorly maintained one it's a whole 'nother story involving wads of cash and piles of frustration. Try to determine what sort of maintenance this one's had before you buy it.
This one has some red flags- broken odometer, 'never used' the 4X4, excessively worn interior and panel damage...I'm not saying it's good or bad, I'm saying look carefully before spending your money. XJ's are not rare or hard to come by.

Coolant, as mentioned, is an excellent starting point. Taking a peek under the oil filler cap with a flashlight is another. Clean? Good. Sludgy? bad maintenance.

Next thing to check is the underside. You are in the road-salt belt and frame rust is a big deal.
Check the floorpans and rear package area floor (moderately easy fix) and frame rails (more difficult repair if repair is even possible). Particularly around the front mount points for the rear leaf springs, that's a bad spot to find heavy rust.
You are most likely going to find rust, it comes with the territory. You need to determine whether the severity and location is within your skills to repair (or not) before you buy.

Pull the air cleaner and check for oil in the filter box. If there's some in there, at best the CCV is clogged, at worst you have ring issues.

Mild lifter tick is entirely normal at this mileage. Any other engine noises are not.

Check around the transmission breather tube, middle of the firewall behind the engine. If the trans overheats the breather belches fluid. Look for signs of it. The AW4 is a tough transmission but does NOT like being overheated.
Shifts should be quick and firm, not mushy or delayed.
At 45mph or above, hold a steady speed and lightly tap the brakes. RPM's should jump up about 300, then drop right back down. If they do your torque converter lockup is working. Make sure it is.

Make a couple low speed figure 8's and listen for chirping, clanking or any steering wheel jerking.

Check inner sidewalls of all 4 tires for oil stripes. Brake leaks or axle shaft seal leaks will show up there.

Given the age, mileage, condition and price- you will be making some repairs, somewhere. The idea is to find out where and roughly how much $$ you can expect to fork out before making your decision.

VFQuake

I'm VERY GLAD the lady who I was buying the red XJ from blew me off, because right after, I found THIS. Very clean, runs fantastic, everything seems to be in order, the lift / 31s don't hurt either!