I have looked all over The forum to try to find an answer to a problem I have been having on my 2000 XJ.
Alternator gauge is showing a nice strong charge but the battery is very questionable. I do plan on replacing battery soon.
Heres the deal-
Starts up nice with jumper cables, the idol is smooth as silk and runs like my baby should.....until it reaches normal operating temperature then starts sputtering and farting until it stalls out, fairly quickly. I can keep it running ruff with gas peddling- but when I let off it quickly sputters out.
Could it be, because I don’t know, if the electric fan turns on it kills the electrical requirements to keep running???? And honestly I don’t know if the fan is on - because I am in cab trying to keep her running..... I love her.

udate!
No up side o2 sensors. Both gone...
Two down flow- Look ruff but I see them....

Both manifold sensors were replaced with big bolts...
.
omg Jeep... help?

 

If you love her, get an OBD2 scanner (can be had on amazon for $25) so that you can get a look at the fuel trims and throttle position. Your symptoms point to a bad O2 sensor, and the fuel trims will help show that.

As for voltage/battery suspect, you can put someone in the cab while you monitor the battery terminals with a multimeter. Or vice-versa. Yes, as loads increase on the system (like electric fan) it can cause problems. But I doubt your fan is coming on at normal operating temperature. It is more likely that when your vehicle gets warmed up and goes into closed-loop mode (using the o2 sensors for fuel trim calculations) that it is getting some bad numbers from the sensors.

 

Awesome Help! Thank you!!!!

 

A country boy would put a second battery inside of the car on the passenger floor. He would have jumper cables to it then to the battery. Then he would run the car and see if that works. If it does you know what your battery. All assume that since you can jump the Jeep that means you have a secondary vehicle around that you can pull a battery from...
Of course, an educated man would go to auto zone they have them put it on a tester...

 

Hehe, nice to know i'm not the only crazy one out there. Been there done that.

Agree with getting it tested, it's usually free at most places.

 

And the XJ is known to be super picky about battery condition. I would wager that the battery condition is exacerbating the O2 sensor issue. If you haven't changed the O2 sensor(s) in a while, I'd just go ahead and buy NTK sensor(s) and replace them regardless as they are a maintenance item.

 

Excellent advice by all! Funny too!!
Thanks so much-

 

Update- did as everyone advised- went to go look at my O2 sensors, and prepare for some wrenching.
The two down stream O2 sensors - Look ruff.

The two upstram under manifold are GONE.
Replaced with large bolts.
And someone has removed the connections on top side wire looms....

gotta love used Jeep.... please Chrysler bring back the XJ I will buy 5.

Any help- would be appreciated. Thanks!

 

Well, that would explain the problems when things get up to temp - exactly what Jordan said, it's fine until it starts looking to the O2 sensors for data.

Can you find where the original sensor wires were cut?

Have you ever had the Jeep running or are you trying to bring back a non-runner? I'm curious as to how the Jeep ever ran without the O2 sensors... possibly some sort of emissions cheating device that fakes out the computer?? If the P.O. (or maybe P.O.S) did something like that, I'd look for where they might have mounted such a device and look for unterminated wiring around that location.

 

Also, on a side note - I agree completely on bringing back the XJ. They have these Elizabeth Warrens (i.e. fake Cherokees) nowadays, but as far as I'm concerned those things might be better named "Grand Compass"es since it's really hard to tell which is which sometimes...

There's no reason why we can't have a uni-frame "AMC station wagon" with the Wrangler suspension and engine/transmission configurations!! Or, in my dream world, Trump makes Jeeps great again and allows the EPA to certify the 4.0L engine for new production and allows the legend to live on!

 

Looks like the 02 sensors are problem number one...On a side note most 90s-up chrysler products won't run without your foot on the gas if the system detects a weak battery and/or bad charging system...Not like the older ones where they'd run fine with a no charge/bad battery condition as long as you didn't stall it....

 

The new Cherokee model came before they started making the Compass look like them. Nice car and I do love my used trailhawk with 3.2l engine with 271 HP, but it's a bit of a beast for serious offroading. I have the Comanche for that. Now if I could get that engine in a stickshift in something more barebones like the old XJs or YJs, for under $25k I'd buy it. Nowadays a wrangler is north of $32k.