2001 Cherokee Misfires #5 After new Plugs and Coil Pack
08-08-2014, 07:56 AM
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Model: Cherokee
2001 Cherokee Misfires #5 After new Plugs and Coil Pack
Hello,
My gf's 2001 Cherokee was running rough so I changed the plugs. IT was still running rough so I changed the coil pack. Now it throws the code (p0306) for cylinder 5 misfire (and I feel it misfiring).
The engine seems to run better in some aspect when I'm on the gas but the idle now worse. Like it's a new problem. I had to come to work today or I'd be wrenching on it right now. I'm wondering if anyone here has any ideas. I'll check the coil pack to see if it's good and pull the plug to make sure nothing happened to it somehow but after that ?????
Has anyone ever changed the PCM harness? Is it "easy enough" to get to?
My gf's 2001 Cherokee was running rough so I changed the plugs. IT was still running rough so I changed the coil pack. Now it throws the code (p0306) for cylinder 5 misfire (and I feel it misfiring).
The engine seems to run better in some aspect when I'm on the gas but the idle now worse. Like it's a new problem. I had to come to work today or I'd be wrenching on it right now. I'm wondering if anyone here has any ideas. I'll check the coil pack to see if it's good and pull the plug to make sure nothing happened to it somehow but after that ?????
Has anyone ever changed the PCM harness? Is it "easy enough" to get to?
08-08-2014, 08:18 AM
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Year: 2000
Model: Cherokee
Engine: 4.0
P0306 is cylinder 6 misfire. You probably did not properly install the rubber boot that goes on the last/furthest plug. I'm willing to bet on it...
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thelebowski69 (04-16-2023)
08-08-2014, 09:03 AM
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New issue after work done= revision of work done.
Plugs gap-checked before installing? Never trust the factory, but check.
Plugs seated correctly and snug
Leads connected firmly
Any other components disconnected while doing the job?
Plugs gap-checked before installing? Never trust the factory, but check.
Plugs seated correctly and snug
Leads connected firmly
Any other components disconnected while doing the job?
Last edited by Roler; 08-08-2014 at 09:05 AM.
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thelebowski69 (04-16-2023)
08-09-2014, 12:04 PM
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Year: 2001, 1997
Model: Cherokee
Engine: 4.0L
How do the plugs look?
Keep in mind the problem may be mechanical not electrical. To fix the misfires on my 01 the head came off and went to the machine shop... Low compression from exhaust valves. That was 6 years ago after new dealer cam & crank sensors and new dealer coil pack.
Keep in mind the problem may be mechanical not electrical. To fix the misfires on my 01 the head came off and went to the machine shop... Low compression from exhaust valves. That was 6 years ago after new dealer cam & crank sensors and new dealer coil pack.
08-09-2014, 05:39 PM
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Year: 2000
Model: Cherokee
Engine: 4.0
Come on guys... He just didn't get the rubber boot properly installed over the plug. It's the furthest plug near the firewall and with the coil pack you tend to bend the boot and miss the plug. Been there done that.
08-10-2014, 12:26 AM
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Fixed
Thanks friends. It turns out (believe it or not) it was a bad plug. Brand new too. I did gap them. Okay ;/ maybe I didn't have the coil pack seated but, I checked man, it was in place. Thanks for the help. First time I ever got a bad plug from the shop.
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08-11-2014, 07:48 AM
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Not sure what the issue is. I read on some forum that those trucks don't like platinum plugs. I put a copper one in and it started firing just fine.
The gap on the platinum was good, the plug was all wet (so we're getting fuel) and it looked like it fired sometimes but just not consistently.
It purrs like a kitten now.
The gap on the platinum was good, the plug was all wet (so we're getting fuel) and it looked like it fired sometimes but just not consistently.
It purrs like a kitten now.
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