Just found a project vehicle for my Daughter.   Went for a test drive last week (been sitting since then), and when we went to pick it up this week, the battery was dead...tried jumping...got it to crank fine, but no start.  The prior owner had been firing it up occasionally, and had started it once before I got there (and it fired up fine when we went for the test drive).

Got it towed home, and did some very basic checks (it was late and cold by the time we got back)

Pulled the battery from another vehicle, and it cranks strongly, but still won't catch.

There's fuel at the Schrader Valve (haven't checked the pressure, but pressing the valve gives a spurt of fuel that builds up on cranking again)

I looked up the Crank Position Sensor issues, and pulled at the plug (infinite resistance at pins b & c).

Can the CPS be bad even if the resistance is correct?

I helped her out with getting it, but she's going to pay for (most) of the parts (I'll help with the labor)...I know the 'gold standard' is a Mopar CPS...can a cheaper one be used, at least to test it out?   (When I work on my daily driver BMW, I'll figure out who the OEM manufacturer was and go with that...it's often 1/3 or 1/2 the price of the BMW labeled parts...can that work for the Jeeps too?, if so, who made the Mopar part?).

Any other suggestions (Going to check for a spark, fuel pressure, etc today if it stays nice enough) to look at?

Thanks!

Went through this on 2x XJs I've owned... a 99 and a 00 both 4.0L

Start with new CPS and CKP... make sure you get MOPAR units for this, had problems with several BWD units before coming to that realization

IF you have an early 99 you probably still have a distributor/ignition wire setup, which makes life easier (the late 99-01 have a massive ignition control module/coil assembly that can cause all kinds of goofy hard to diagnose problems)
If you have the latter, also replace it.

Go ahead and fire it up. If it doesn't start or idles super rough reply back here. There's more!
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Get Mopar sensors/sending units. Dont buy BWD or whatever brand the big parts stores have.

Swap them out and report back

Above and get a fuel pressure gauge [maybe autozone loans them out] to check fuel pressure, just because there is some fuel pressure doesn't mean it is enough fuel pressure to actually fire the engine.

You can always cheat a little with some starting fluid.

Thanks for the suggestions.   I'll try them all...figured that might be the case.

(There's plenty of cars around for her to drive...and to pass emissions, I'll have to (maybe) swap an O2 sensor and find the reason for the Evap code...apparently they are intermittent per the prior owner.)

Definitely keep thread updated, will watch

My 2001 did that.  It was the fuel pump.  It is will start a little on a spray of starter fluid, then it’s fuel.

Make sure theres gas in it
Turn key do you hear the fuel pump run a few seconds
30$ mopar crank shaft position sensor.

There's gas...and best prices I'm seeing are $90 on line.

I suggest getting a fuel pressure gage. The fuel pressure regulator is built into the fuel filter which sits on top of the tank. I had a 97 that was getting too much fuel do to the pressure regulator being bad. The other posters have given good advice.

I couldn't do much to it yesterday (despite the warmer weather)...changed the oil in my car, did some misc. cleaning in it and another car, then put the battery back into the Wrangler (that we tried in the Cherokee), put air in some tires....

The battery (Jan 2015 sticker) that was in the Cherokee was on the charger all night (650 CCA, and the Solar tester I have (not a real load tester, but it works) measures about 540 CCA at 60 minutes off the charger), so it's back in the Cherokee (and currently with a trickle charger hooked up).

So, on to some testing....no key...I text my Daughter...Oops...has both keys with her and won't be back until the late evening......

Hopefully this coming weekend will be nice enough to work on it and do some more diagnostics.

Thanks again for the suggestions...
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Edited:
Started fine today twice....daughter drove it a couple of miles....not sure if it was because I unplugged the Crank Sensor to test it (and sprayed Kroil on the bolts, along with ground points, O2 sensors, etc, to get ready to work on those things)...

Probably still going to replace the Crank Sensor as a precaution.

Updated in the post above this one.

Sounds like a fun project to do with your daughter.  Would love to see pictures of the Jeeps transformation as your daughter makes it hers.

If I remember to get the pics:

Gold colored.

So far (brief survey, some is 'known but not seen by me' issues from the prior owner) what needs done:

Throws an intermittent O2 and/or Evap code (not stored after the battery was dead).

Crank Sensor (Mopar Replacement).

Slight leak of Oil around the Valve Cover gasket.

Slight (very slow) coolant leak (appears to be around the thermostat housing...going to get dye for it and find it)...could be the thermostat/gasket, housing or the water pump is right below it.   More smelling the coolant than seeing it.

Driver's door hinges (already have the pins/grommets to replace) let it sag.

Driver's door rusted through on the bottom edge (1/2")...not sure what to do with it (replace door/cut out and weld in a skin, etc.).

Driver's door wiring was cut at one point so he could run without the door...mostly re-wired, but can't get the window to work so needs checked.

Driver's floor rusted through (Patched with aluminum plate...a good job, but cut through the carpet to do it, so replacement carpet may be in order)...no other rust through in the vehicle.

(Reported by the prior owner)...some 'slipping' in the trans...sounds like a shudder when shifting from 4th to 3rd the way he describes it, but can't get it to duplicate now (my Daughter messaged my Brother In Law (former mechanic, now doing IT stuff) who said that's a strange issue, and recommended we check the U joints as a possible issue causing that...)

Needs upper part of rear seat.

General Cleanup in it (was an outdoor fishing/shooting, etc. vehicle).

Overall, mostly rust free...some tiny bit on the rocker panels and driver's door, but pretty solid elsewhere.

So, overall, probably not a bad vehicle (4.0L, 169k miles) and the trade value was cheap.

Solve the coolant leak asap, overheating is the biggest killer of the 4.0.

Drain the tranny pan & refill, drive a week & repeat, after 3-4 times it will be 99.99% clean fluid. The AW4 is a great tranny that likes standard Dextron 3, i use the cheap gallons that pep boys sells (on sale $9.99), same stuff goes in the transfer case.

I use all junkyard parts (Alternators, starters, drive shafts/axle shafts, even transmissions/transfer cases if needed) plentyful & cheap + i find the oem parts to be much higher quality than most of the parts store stuff available.

Rust has to be dealt (wire brush, prime/paint) with or it will eventually kill your XJ.
Good luck!

Updating a bit:

The Hard start was a bad battery (mostly).   Swapped a good battery in, and it does fine.   The old battery would take a charge (read 12.7v after coming off the charger, and my Solar tester would tell me it had 530 CCA's...but use it barely at all (try to start once) and the voltage drops to 10 or less.   Now have an Interstate Blem in it.


Throws an intermittent O2 and/or Evap code (not stored after the battery was dead)....Found 2 bad rubber connnectors in the Evap system.   Still throws an intermittent O2 code (but my daughter cleared it, drove 50+ miles, got it inspected and emissions tested, so I'll put that on the 'not critical' list).

Crank Sensor (Mopar Replacement)....bought a Standard Motor Products unit (came in Amazon quickly), seems to work fine.  The Mopar unit came in yesterday, and I'll swap them and keep the Standard part as a backup.

Slight leak of Oil around the Valve Cover gasket.

Slight (very slow) coolant leak (appears to be around the thermostat housing...going to get dye for it and find it)...could be the thermostat/gasket, housing or the water pump is right below it. More smelling the coolant than seeing it....Found the leak (using UV dye)...drip (very little) at the heater hose coming into the water pump.   I'm going to replace the water pump/gasket, heater hose, and the thermostat/gasket/housing soon.

Driver's door hinges (already have the pins/grommets to replace) let it sag....Replaced them, the door works good now.

Driver's door rusted through on the bottom edge (1/2")...not sure what to do with it (replace door/cut out and weld in a skin, etc.).

Driver's door wiring was cut at one point so he could run without the door...mostly re-wired, but can't get the window to work so needs checked....rewired, now I only get the doors to unlock (but not lock).   Ordered a switch unit to try next.   Still has 2 wires (coming from the 3 row connector at the body...brown with a red stripe and solid green) that don't have matches on the door side.

Driver's floor rusted through (Patched with aluminum plate...a good job, but cut through the carpet to do it, so replacement carpet may be in order)...no other rust through in the vehicle.

(Reported by the prior owner)...some 'slipping' in the trans...sounds like a shudder when shifting from 4th to 3rd the way he describes it, but can't get it to duplicate now (my Daughter messaged my Brother In Law (former mechanic, now doing IT stuff) who said that's a strange issue, and recommended we check the U joints as a possible issue causing that...)...haven't done anything with it yet, but my Daughter got it to 'shudder' when trying to downshift at highway speed from 4th.   Pushing hard on the gas causes it to downshift fine, but if you give it gentle gas in 4th you get the shudder.   Possibly a solenoid?...still going to change the fluid/filter.

Needs upper Lower part of rear seat.

Unstuck the rear driver's side door (rusted and frozen at the mechanism), and adjusted the hatch to work easier.