2001 4.0 XJ Misfire
#1
2001 4.0 XJ Misfire
I have an '01 Cherokee Sport 4.0 straight 6. it's been running rough for about a month or so now. I ran the codes and I have a misfire in cylinders 4, 5, and 6. I replaced the plugs and the boots and I still have the same problem. I want to say that it is the ignition coil, but I don't want to throw out $110-150 if that isn't the problem. Any suggestions on what else could be causing this problem would help a lot.
Thanks, Jace
Thanks, Jace
#2
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Year: 1998
Engine: 4.0
Be sure to have the correct spark plugs in it first, then read this:
http://www.naxja.org/forum/showthread.php?t=938256
Edit: Welcome to the forum, btw.
http://www.naxja.org/forum/showthread.php?t=938256
Edit: Welcome to the forum, btw.
Last edited by 4WD4EVER; 10-04-2015 at 08:48 PM. Reason: Add info
#3
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Year: 1994 1993
Model: Cherokee
Engine: 4.0
I know some of the newer ('99+) XJs had a "heat soak" problem where the heat from the exhaust manifold would affect injector function. But I am thinking that just applied to one injector? Maybe someone else can provide more info on this specific problem I am thinking of.
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Year: 1998
Engine: 4.0
After you make certain you have the recommended plugs in it and check the coil (which I don't think is the problem), I think you need to check the cyl. head casting #. Here is some info on that:
https://www.cherokeeforum.com/f2/00-...erview-118922/
Let us know what you find.
Also, what are the specific codes being thrown?
https://www.cherokeeforum.com/f2/00-...erview-118922/
Let us know what you find.
Also, what are the specific codes being thrown?
#5
I forget which spark plugs exactly I put in them, I want to say I put Champion Double Platinum. it's been about 3 weeks since I changed them and the exact brand is slipping my mind. What kind of plugs would be the exact ones? I have a buddy who works at O'Reilly and I went in there and he did a computer search and these were the "preferred ones" I just don't know what exactly it is. My check engine light is on all the times but after 20-30 minuets of driving it starts flashing and it takes 2-3 seconds to accelerate after I hit the gas, almost like a sputter.
#6
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Year: 1998
Engine: 4.0
If I were you, just for the sake of getting it correct, I would go with the OEM plugs (at least for now). Should be plain, old Champion copper. IDK the exact # for your MY, you'll have to ask/look up.
Read the other link I provided on the cyl. head casting before you throw more time/money into this. Then go from there.
Edit: IDK, someone else will have to chime in. Maybe the platinums are the preferred plug for it.
Read the other link I provided on the cyl. head casting before you throw more time/money into this. Then go from there.
Edit: IDK, someone else will have to chime in. Maybe the platinums are the preferred plug for it.
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Year: 1998
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You're welcome. Let us know what you find out from the coil test.
Edit: A cracked head can cause the symptoms and throw the code you're describing. Just keep that in mind. I'm not saying that's it or not.
Edit: A cracked head can cause the symptoms and throw the code you're describing. Just keep that in mind. I'm not saying that's it or not.
Last edited by 4WD4EVER; 10-04-2015 at 09:24 PM. Reason: Add info
#10
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Year: 1998
Engine: 4.0
Just found out that if you buy spark plugs from the dealership they will sell you NGK ZFR5N spark plugs. These are nickel plated, not platinum. These are the OEM replacement of the Champions. You may want to consider swapping out the platinums. Your call.
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Year: 2015, 2012
Model: Grand Cherokee (WK2)
Engine: 3.6L
Every 2000-01 XJ 4.0 has a known factory casting flaw in the head.
It cracks, usually between #3 and #4.
Your diagnostic path may eventually lead you to this. I don't think a minor variation in plug type is going to cause your problem.
It cracks, usually between #3 and #4.
Your diagnostic path may eventually lead you to this. I don't think a minor variation in plug type is going to cause your problem.
#12
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Year: 1998
Engine: 4.0
As far as the plugs go it has been documented by CF member "noredplz" that the incorrect plug is known to cause misfire/runnability issues. I would think it best to rule this cheap possibility out.
OP, after you've checked your coil for peace of mind, I would get all of the engine/battery grounds cleaned up well. Here is a link to assist you with the locations:
https://www.cherokeeforum.com/f2/eng...130071/index2/
Then, I would check the CKP (crank position sensor). Here is a link for that:
https://www.cherokeeforum.com/f51/testing-cps-5563/