'00 XJ Engine troubles. (idling, power...)

Ok so I've had my '00 XJ for 3 weeks and am having problems.

Its a 4.0, auto, selec-trac

Today im leaving college, heading home for break, and coming to a stop light the check engine light comes on, and it starts shaking and idling rough.

I drive for about 1 more minute before i can stop, and the check engine light is flashing. According to the owners manual, that means engine trouble and cat. trouble is about to happen?? So i drive the Jeep back to my apt, any time the engine is under strain it seems to bog down and is lacks power. When its in park or neutral it seems fine, but as soon as i shift to a drive gear it starts shaking, the RPM's drop some and the needle bounces. And during driving, its laggy on power, and shakes.

Ideas???? I haven't even looked at it yet, Im bumming a ride home and wanted to throw this post out there before I leave.


Thanks,
Aaron

you have a cylinder misfire... thats about all I can tell you... check plug wires, spark plugs...could be a faulty injector

Well it's kind of tough to give you an idea based on the description.
But, did you check your temperature gauge?

I have a 99XJ and about a couple years ago had an issue with the thing bogging down right after you try to accelerate from a stop. This happened after the car had been running a while.

Well, once I saw that the temperature gauge was reading "0" I realized that the problem was the engine was running rich. The engine had warmed up but the computer hadn't realized that it was warm so the mixture was too rich. I used some electrical connection cleaner spray on the connector and temperature sensor contacts, rinsed it out with some alcohol, dried it, applied some dielectric grease and reconnected it. I haven't had any problems since.
Oh this also set a check engine light.

Another problem that I've had at idle is related to the idle air motor. When the passage in the throttle body is dirty this causes the engine to stumble and even die at idle. For this I removed the throttle body and spray the air passage with throttle body cleaner until the solvent starts to come out clean. The problem is gone after that.


MAP

good call digger i too think its a misfire. I think and its just me , I would let the engine run and pull each plug wire to see if the engine sounds different. if you pull one and the engine sounds the same, than thats your misfire cylinder, right digger?
ASE cert. only 3 years though, just a rookie!!!

I don't have plug wires, I guess its a coil that I have.

(new to this engine....)

Have you tried pulling the code off the computer yourself to see what the problem is? The on-off-on-off-on-off method supposedly works (do a search for pulling trouble codes or something to that effect). Also, holding down the trip reset button and turning the ignition on and letting go of the button *SHOULD* also scan the computer, but there is much arguement about that one. Thats the only one I can get to work on my 99, it will make all the needles move and all like it's scanning, but many say that just scans the instruments, and not the computer, even though i've seen several sites on the net that say Chrysler designed it so that you could pull the codes that way.

I would say see if you can figure out how to do the on off method by doing a search on here, or if somebody else chimes in on how to do it. I never can remember how many times your supposed to cycle, and to that starting points and stopping points.

Once/if you get the code(s) pulled off of it, go to the website below to find out what it stands for. This is the best site i've seen yet.

http://autorepair.about.com/cs/troubleshooting/l/bl_obd_main.htm

Good luck. BTW, where in NC are you?

Ok here's the deal. I was trying to pull codes, and got nothing. I got the codes to pull, like where the needles dance around, but I got no actual codes.

I limped it down the road to Advance, put it on thier computer. Well 3 cylinders were misfiring. I pulled the plugs, had carbon build up on them. Hmm...bad gas? I added 5 more gallons of gas, and now she runs like a champ. Although the check engine light is still on. So i put some additive to get the water out, filled up the rest of the tank with gas, and hopefully that will be the problem.

Oh yea, home home is near hickory, but I go to App State.

99XJSPORT06 said:

Have you tried pulling the code off the computer yourself to see what the problem is? The on-off-on-off-on-off method supposedly works (do a search for pulling trouble codes or something to that effect).

Click to expand...

This works, but only on pre-OBD-II XJs - '96 (IIRC, OBD-II came in a year *before* the '97 changes) through '01 require you to plug into the diagnostic port below the driver's side kick panel with a code reader in order to obtain them. I'm also not entirely certain which year ranges the key trick works for, but I'm fairly certain 84-86 used a different method to obtain them.

Some Autozone stores would pull diagnostic codes for you for free, but several people have reported that they no longer do. My local one will (depending on who's behind the counter), but YMMV.

Also, holding down the trip reset button and turning the ignition on and letting go of the button *SHOULD* also scan the computer, but there is much arguement about that one.

Click to expand...

To the best of my knowledge, nobody has ever obtained a diagnostic code on an XJ this way. From what I've read, certain Chrysler models *could* display codes with this method, but they weren't XJs. Take that for what it's worth - I could be wrong, but certainly neither my previous 2001 nor my current 2000 will display codes using this method.

Thats the only one I can get to work on my 99, it will make all the needles move and all like it's scanning, but many say that just scans the instruments, and not the computer, even though i've seen several sites on the net that say Chrysler designed it so that you could pull the codes that way.

Click to expand...

Beware of what you read on the Internet; not all of it is necessarily accurate. On the XJ, this seems to be solely an instrument / warning light test.

You say you've got a 2000... There were two recalls in that year per Alldata, as well as various TSBs for misfires, etc. FWIW, the #3 cylinder injector seems to be a common problem spot in this year.

Take the VIN down to your local dealer and ask for a VIP report - this should detail all recall / bulletin work performed on the vehicle. While they're pulling that, you might also ask them to get the build sheet for you - can't hurt to know how it left the factory.

you need an OBD II reader to get the codes.
there are no spark plug wires because it (the 2000 XJ) has a coil on plug design which fires two cylinders for each coil (3 coils 6 plugs). as i understand it the coils fire two cylindrs at a time whether or not the piston is in intake or exhaust...say it fires the 3 and 5 cylinders...it fires them both fuel or not.
there are some guys here who can tell you what voltage or resistance drop there should be for each sensor...checking each sensor this way can eliminate or narrow down where the problem is.
so far the ideas above sound pretty good.
the ghost in my XJ is a misfire in the #3 cylinder...sometimes it happens and sometimes it doesnt...i am still not sure why...thought it was cracked head, but the head is fine (so far).
oddly enough higher octane fuel seems to be the cure...but jeep reccomend 87 not 89 so i may be risking other problems to solve #3...
i have heard similar problems as yours on here...somebody suggested o2 sensors...another the TPS...and another a rich condition.
beware that the rich condition may shorten the life of the catylitic converter.

just stick with it and try not to get frustrated because once the bugs are worked out the XJ 4.0 is a real workhorse engine.
get the code (dealer or shop with reader or if you have the cash buy a reader) and hopefully solve the problem.
best luck
^^ what he said...lol i gotta learn to type faster!

Yea thanks guys. I took it to Advance earlier and hooked it up to their computer. I got:

- misfire on 3 cylinders
- o2 sensor problem
- ignition coil

I still think that it is bad gas. As soon as i added some new gas it began to run better. The jeep is running fine now, i put in some good gas and some of that stuff to get the water out. The check engine light is still on. I'll unplug the battery, to try and reset the computer, then drive it for awhile and see if im getting the same misfire readings.

Not sure if this will help or not, but it's a suggestion. Try running a good can of fuel injector cleaner through it with your next tank of gas. Run the tank down to almost empty (but don't go empty of course), add a container of fuel injector cleaner in there (you WILL need a PLASTIC funnel, I learned the hard way exactly how stubborn that flap in the gas tank is..lol), and then fill er up.

I did this on mine a while back and noticed a dcent increase in performance, and a slight (and I do mean SLIGHT) increase in MPG. I used STP fuel injector cleaner, comes in a small black bottle and was $2 or $3 and some change at Autozone.

Again, may not help, but for the price of the stuff, it worth it to give it a try.


as the pulling the codes yourself, I guess Chrysler got wise to people doing it their self and stopped making it possible?

Oh while on the subject of codes, you mentioned your light was still on. Un plug the negative cable of the battery and let it sit for usually 10-20 minutes or so then plug it back in. This should reset the computer and turn the light off. Unless of course, there's still a problem, in which case it will come right back on again.

JeepinAaron said:

Yea thanks guys. I took it to Advance earlier and hooked it up to their computer. I got:

- misfire on 3 cylinders
- o2 sensor problem
- ignition coil

I still think that it is bad gas. As soon as i added some new gas it began to run better. The jeep is running fine now, i put in some good gas and some of that stuff to get the water out. The check engine light is still on. I'll unplug the battery, to try and reset the computer, then drive it for awhile and see if im getting the same misfire readings.

Click to expand...

disconnecting the battery will not erase codes or turn out a CEL on a OBDII system. ('97+) They must be removed by using a scan tool or, in time, the computer will turn out the light if the reason for the code is gone...but that takes like a 100 drive cycles.

Resetting the cel depends on the condtion that set it, some will reset on the fly, others take a number of full cycles, full cycle being stone cold-operating temp-back to cold. Some can reset in 1, some in 5, some in 20. If you plan on keeping the jeep go buy one of the code scanners from Auto zone, I picked up one a few months ago, either $150 or $250, forget now. It has been usefull and not just on our jeeps but a couple of neighbors know I have it. Its almost paid for 'sure, you can borrow it, OH, that reminds me, need to pickup a couple more cans of Fosters lager' :laugh3: works sometimes...

Yea i tried disconnecting the battery last night. The engine light went away for about 5 seconds, then it was back, as was the bad idling problems. I may replace the O2 sensor today, since that was one of my error codes. I'm still hoping though that its bad gas.


But explain this one to me. During idle, while its just sitting there, the Jeep runs fine. Put it in drive, its fine. Put it in REVERSE, and it bogs down, starts shaking. I have to turn it off and restart it, to get it to idle correctly.

JeepinAaron said:

Yea i tried disconnecting the battery last night. The engine light went away for about 5 seconds, then it was back, as was the bad idling problems. I may replace the O2 sensor today, since that was one of my error codes. I'm still hoping though that its bad gas.


But explain this one to me. During idle, while its just sitting there, the Jeep runs fine. Put it in drive, its fine. Put it in REVERSE, and it bogs down, starts shaking. I have to turn it off and restart it, to get it to idle correctly.

Click to expand...

No clue, I don't do automatics other than to check fluid and if it does not work take it to my mechanic friend and let him fix it...

Don't replace the O2 sensor just yet. If the engine is running rich and it appears that it was, the O2 was merely detecting the rich condition. It doesn't appear to be the root cause. If the O2 sensor was not reading correctly all the cylinders would have been running rich not just 3 of them.

My guess is that those 3 cylinders weren't firing properly. It may just be an ignition related issue. Were there any TSBs on the coils that sit on the plugs?

Another possibility is that those 3 cylinders were running rich. If you cleaned them and the engine started running fine, it maybe be temporary until you get excessive carbon buildup again. The fact that the a code for the coil came up makes me lean toward the ignition system being the issue.
It's just not burning off the fuel in those couple cylinders. You should try taking care of that as soon as you can. Extra unburned fuel getting to the catalytic converter will cause it to get extremely hot and eventually lead to failure if the condition is present for an extended period of time.

MAP

Yea here is the update on my problems.

The engine codes have all gone away except for the Ignition Coil.

Here is what is happening. When the Jeep is in N/P/Drive everything is fine. If i put it in reverse, and mash the gas, then it bogs down, and starts idling rough. This rough idle is corrected by turning the jeep off and refiring it. I don't quiet understand that.

Today for a few hours, the engine light went off and it wasn't throwing codes. It is now back, Ignition Coil. All the parts places have to order one, so I will replace the coil bar early next week.

Something else interesting: I'm blowing coolant out of the radiator. I've checked everything over, hoses, the radiator, and it doesn't seem to be leaking. It looks like its blowing the fluid out of the cap. Bad cap??? This is a new problem also.

Well, I wouldn't drive it that much if I were you with a bad cap on it. No sense in running the thing out of coolant and overheating it, but thats my personal opinion.

Ok.. those symptoms (CEL, mis-firing, blowing coolant) indicates to me a blown head gasket.

Of couse this is a seat of the pants diagnosis but if I was you i'd take it to a mechanic to confirm.

Ok, so here is the deal. With all of the above problems I had listed, I think everything is fixed.

The problem, that caused the mis-firing, was bad gas. After getting rid of the gas, and all that jaz, I replaced the plugs, went ahead and drained the transmission, changed the filter, and put in new fluid. After all of that, the jeep was still running bad and missing when put in reverse. Since i only had the jeep for about 3 weeks, the jeep dealership decided to look at it. They said all looked well, and that the check engine codes just needed to be changed.

now it seems ok.

the starting is still lagging, i think i am going to go ahead and replace the ignition coil.