My first problem...

[RageOfFury]

I come home this evening after work. Hop into my Jeep and head to the restaurant. I notice immediately that there is something wrong. The engine runs really rough, the whole jeep shakes when idle, very little power when I press on the gas and the check engine light turns on. So instead of going to the restaurant, I headed over to the dealership. They now have her, will check her out tomorrow and let me know whats wrong.

I bought her 1 week ago and already a problem. Jesus!

 

[oddball]

Let's hope it's not a serious issue.

 

[valvestem]

Battery was the first thing that came to my mind FWIW.

 

[RageOfFury]

Battery was the first thing that came to my mind FWIW.

What does the battery have to do with the engine running rough/shaking?:-k

 

[Marlon_JB2]

What does the battery have to do with the engine running rough/shaking?:-k

Not enough voltage in the system to run all of the electronics, throwing everything out of whack.

 

[kj924]

What does the battery have to do with the engine running rough/shaking?:-k

I have read many posts with the exact same senario.

Hopefully that's all it turns out to be. [-o<

 

[kbooneKJ]

yup mine did that too when my battery was bad. i had to hold the gas while putting it into reverse and drive or else it would die. i got a new battery and problem solved

 

[RageOfFury]

And that would turn on the check engine light? Make the engine run rough, shake the whole jeep, loose power?

If it's the battery, wouldn't she be hard to start? Because she isn't, starts up no problem.

 

[JeepJeepster]

Checking the codes would of told you a lot.

 

[RageOfFury]

Checking the codes would of told you a lot.

Well the dealer will do that. I have the Gold 5yo/100 000KM warranty on it, so I'll let them fiddle with it. Won't cost me a thing.

 

[Ry' N Jen]

The battery was my first thought as well...
Then, I recall the same issue!
Bad spark plugs!

 

[kb0nly]

Yep, to answer your question that battery can cause the check engine light and crap. The CEL comes on when something in the system ain't working right, low battery voltage screws up a sensor reading to the computer, it runs like crap, and pops a CEL. Even though the battery has enough power to crank the engine once it gets started then there isn't enough power to go around and crapola time.

I know it sounds stupid but as you can see by the replies its happened to many a KJ owner.

 

[RageOfFury]

Well if it's just the battery then that should be an easy fix. The dealership is currently checking her out. So I should hear from them sometime today.

 

[Powerslave]

It won't be the battery...

 

[valvestem]

It won't be the battery...

Then what will it be pray tell?

 

[Powerslave]

Then what will it be pray tell?

Could be many things, but it won't be the battery. Someone else here had a similar problem, but I don't think they ever said what it was.

IF the CEL comes on solid, with a rough engine idle, studering or stammering; it is more than likely, an emissions related problem. That being sensors, vacuum lines, EGR, and so on. Sure, it can be plugs, coils, injectors, but it's all part of the emissions systems. Then, it can be low charge voltage, but the battery light would be on as well.

If the CEL comes on, and blinks under acceleration, it is a more severe problem, and DO NOT drive it...

Other CEL conditions are transmission failures, those you will know (feel).

I am only saying, it WON'T be the battery... I just can't see it being a battery when, the car is RUNNING, it is producing the charge voltage. If it falls below 13V, the battery light comes on. I have NEVER, EVER had a weak battery cause this kind of behavior, in ANY of my cars. I'va had three three cars that were 2006 or better, when the battery was BAD, it was bad... My 2000 avenger had all the doo-dads, and a weak battery NEVER caused those issues. While I am sure it has happened, it can't be that ALL the time.

 

[tjkj2002]

Could be many things, but it won't be the battery. Someone else here had a similar problem, but I don't think they ever said what it was.

IF the CEL comes on solid, with a rough engine idle, studering or stammering; it is more than likely, an emissions related problem. That being sensors, vacuum lines, EGR, and so on. Sure, it can be plugs, coils, injectors, but it's all part of the emissions systems. Then, it can be low charge voltage, but the battery light would be on as well.

If the CEL comes on, and blinks under acceleration, it is a more severe problem, and DO NOT drive it...

Other CEL conditions are transmission failures, those you will know (feel).

I am only saying, it WON'T be the battery... I just can't see it being a battery when, the car is RUNNING, it is producing the charge voltage. If it falls below 13V, the battery light comes on. I have NEVER, EVER had a weak battery cause this kind of behavior, in ANY of my cars. I'va had three three cars that were 2006 or better, when the battery was BAD, it was bad... My 2000 avenger had all the doo-dads, and a weak battery NEVER caused those issues. While I am sure it has happened, it can't be that ALL the time.

That's funny,had a '03 KJ come in about a week ago,ran rough,no power,and the MIL was on throwing about 12 codes which none had to do with the battery and it just had a bad battery.Replaced the battery and all was good,no more codes,ran smooth,and had all the power back and that has been about the 20th one exactly like that over the last 10 months at work.


It can be other problems but the most common problem for the OP's problems has been a battery,there are other causes also but the battery should be checked 1st even before any codes pulled since the KJ is very picky about it's battery voltage.

 

[Jeepin05]

Powerslave is always so quick to write-off the battery...

Honestly, if the KJ ran great before this, I would bet money it's the battery. I've read so many things with the battery I'm probably going to replace mine soon.

 

[kb0nly]

That's funny,had a '03 KJ come in about a week ago,ran rough,no power,and the MIL was on throwing about 12 codes which none had to do with the battery and it just had a bad battery.Replaced the battery and all was good,no more codes,ran smooth,and had all the power back and that has been about the 20th one exactly like that over the last 10 months at work.


It can be other problems but the most common problem for the OP's problems has been a battery,there are other causes also but the battery should be checked 1st even before any codes pulled since the KJ is very picky about it's battery voltage.

X2...

Although i haven't experienced this on my KJ yet it happened to me in my Pontiac Montana. It was acting weird as hell. I took it to two different shops after i couldn't figure it out, both of which put their diagnostics computer on it, they would replace a sensor, or this and that, and it would act like its maybe running a bit better but the problem would come back. Then it got to winter time and it got cold, the first morning i needed it again it wouldn't crank fast enough to start. So i said fine, i will buy a battery for it since at least i could pull that and re-use it if i get rid of the damn thing. Well lo and behold i replaced the battery and it started right up and all the driveability problems went away, i was shocked. After that i won't discount the battery myth after reading about all the KJ owners that have suffered from the same symptoms online.

Powerslave... Not to be an ass, but why is it lately every time you post its just to discount everyone else and say it can't possibly be this or that???

 

[kb0nly]

Powerslave is always so quick to write-off the battery...

Honestly, if the KJ ran great before this, I would bet money it's the battery. I've read so many things with the battery I'm probably going to replace mine soon.

And here is the main thing....

You can go to Wal-Mart and buy a $60 battery to test it out and see if that cures your problems. If not return the battery and get a refund and your not out anything. That's a heck of a lot cheaper than spending a full day in the shop somewhere. If it does fix the problem keep the cheap battery until you can afford something better, give it a few days and make sure the problem doesn't come back, etc.

Most of the auto parts stores around me will take a battery back same day also, and the better ones will load test the battery and even let you change it right there in their parking lot to see if the battery truly is your problem for free, after all they want to make the sale and sell you something.