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Need advice on mis-fire

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Old 06-19-2014, 04:42 PM
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Default Need advice on mis-fire

Hey, need advice on a mis-fire code(s) on my 2000 xj... Sometimes it says cylinder 3, sometimes 6, sometimes both. Replaced the ignition coil pack about 3 times now, even went lazy and just reset computer and disconnect/reconnect harness... every couple of weeks it does this... Is it just my luck I'm buying bad coil pack or is this something else? Getting tired of it... Really... Tired... Of... It...
Old 06-19-2014, 04:43 PM
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0331 head? Check for coolant in oil?
Old 06-19-2014, 04:49 PM
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0331 head? All I know is it's a 4.0 Straight 6... No coolant in oil...
Old 06-19-2014, 05:15 PM
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It's probably the "heat soak" issue. It's basically where you drive for a while, turn it off, and then start it back up a few minutes later and it throws a code. The poor design of where the injectors are placed too close to the manifold and it gets all that heat and vaporizes the fuel causing the misfire. You can purchase a heat shield that you wrap around those injectors to help but I had the same issue and installed the heat shield and hood vents to help with releasing the under hood heat. I haven't had it happen since and it's 100 degrees here in NC. Good luck
Old 06-19-2014, 05:22 PM
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Yes... I've heard of this "heat soak" from my brother in law when I bought it off him... Where do I get this heat shield?
Old 06-19-2014, 05:38 PM
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Originally Posted by (ThE NoRm!)
Yes... I've heard of this "heat soak" from my brother in law when I bought it off him... Where do I get this heat shield?


I got mine through the Jeep dealership but it should be part #56028371AA. I think it was like $7. I believe it's called an ignition or wire shield or something like that. It's basically like a 3-4 inch off- white cylinder that you cut into 2 half cylinders and zip tie it on. Should be more info somewhere if you google it that shows you how to install it but it's very easy. It's basically a trim and fit.
Old 06-19-2014, 05:42 PM
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This looks like it should be it. There's only one so if you want to wrap more injectors you need to purchase accordingly.


http://www.factorychryslerparts.com/...6028371AA.html
Old 06-19-2014, 05:50 PM
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Thanks... Will try it...
Old 06-19-2014, 05:58 PM
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Like I said, it helped me but when I added hood vents it helped a lot more heat get out. I installed the RunCool hood vents. Should be a picture in my build thread if you wanted to see what they looked like. They were easy to install after measuring 100 times before cutting. I highly suggest them if you're going to be offroading because the heat builds up a lot more driving slow on the trails.
Old 06-19-2014, 06:00 PM
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Or I'll just try the hood vents... Had ground off for at least an hour and it reset... Everything is fine... for now...
Old 06-19-2014, 06:02 PM
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Originally Posted by (ThE NoRm!)
Or I'll just try the hood vents... Had ground off for at least an hour and it reset... Everything is fine... for now...


Just do both. The shield is cheap and takes 5 minutes to put on.
Old 06-28-2014, 11:35 AM
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Ok just went to Advance Auto and bought DEI Pipe wrap (header wrap) to wrap the exhaust manifold to keep the heat down... Hope this works... May use some on fuel injectors too... Never done this... I really hope I do not have to take injectors or fuel rail off... Any advice please call me direct at 440-313-1501 Thanx
Old 06-28-2014, 01:00 PM
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Originally Posted by (ThE NoRm!)
Ok just went to Advance Auto and bought DEI Pipe wrap (header wrap) to wrap the exhaust manifold to keep the heat down... Hope this works... May use some on fuel injectors too... Never done this... I really hope I do not have to take injectors or fuel rail off... Any advice please call me direct at 440-313-1501 Thanx
Be careful using wrap. Do a little research to make sure there's no issues using it on stock manifold. IIRC some materials don't like to be wrapped. By insulating the pipe you hold the heat into it.

This shouldn't be happening in the first place so the best fix is actually fixing it, not adding wrap and vents. I can appreciate the frustration- mine won't even start right now. A frayed wire or bad ground are both possible so a very thorough inspection of your wiring harnesses isn't a bad thing.
Old 06-28-2014, 01:49 PM
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Just decided on doin the leaky valve cover gasket and probably take it in to the local garage for the check engine light...
Old 06-28-2014, 03:26 PM
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Originally Posted by (ThE NoRm!)
Just decided on doin the leaky valve cover gasket and probably take it in to the local garage for the check engine light...
Right on. For like 60 bucks you can pic up a scan tool from parts store. I'm sure the shop will do it for free, but this way you'd have a scan tool. Paint the valve cover while it's off!


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