Cylinder #1 misfire....I've done my searching
I bought a valve spring compressor tool and a fitting kit to thread my compressor air line into the spark plug hole from NAPA. I replaced the #1 springs in about an hour start to finish. Search Youtube, lots of vids on the subject. BTW I'm a couple weeks on the new springs and no CEL. Feels and sounds way better.
Thread Starter
Seasoned Member
Joined: Feb 2013
Posts: 330
Likes: 0
From: Northern Michigan
Year: 2001
Model: Cherokee
Engine: 4.0 V6
Ok cool, can you provide a link for your tools you purchased. I am going to do compression and swap injectors/plugs before I do springs.
My phone wont let me copy/paste the address' correctly. Google air hold fitting kit and valve spring compressor and you'll find what you need. Finding a Youtube video on it is a must if you have never seen it done before.
so the chamber wasnt clean (despite a new head) and you reused however many hundred thousand mile valvesprings on an otherwise brand new head ? something's fishy about all this.
I'd guess the valvespring was the issue. prob hanging the valve open bc it was too weak to shut it. hopefully you had other issues with the old head.
I'd guess the valvespring was the issue. prob hanging the valve open bc it was too weak to shut it. hopefully you had other issues with the old head.
Thread Starter
Seasoned Member
Joined: Feb 2013
Posts: 330
Likes: 0
From: Northern Michigan
Year: 2001
Model: Cherokee
Engine: 4.0 V6
No it's a brand new CW head. Another member on here bought the same head around the same time as me. He discovered a faulty valve/spring. I am going thru the process to see if mine is the same issue. His was isolated to the #1 cylinder only as well.
Senior Member
Joined: Apr 2012
Posts: 578
Likes: 4
From: Ocean, New Jersey
Year: 2000
Model: Cherokee
Engine: 4.0
When did you buy your head? I'm also getting a cyl 4 misfire with a new CW head. Mine was shipped May 2012.
Thread Starter
Seasoned Member
Joined: Feb 2013
Posts: 330
Likes: 0
From: Northern Michigan
Year: 2001
Model: Cherokee
Engine: 4.0 V6
Mine was about that time, I did it in April if I recall correctly. I will check the receipt. I hope it's not a bad batch of bent valves and we each got stuck with one faulty valve. I don't want to pull the head again!:banghead:
Senior Member
Joined: Apr 2012
Posts: 578
Likes: 4
From: Ocean, New Jersey
Year: 2000
Model: Cherokee
Engine: 4.0
Thanks. Worth a shot. I've checked everything to find the root cause with no luck. My case might be different as I had a cyl 4 misfire before the head replacement.
Thread Starter
Seasoned Member
Joined: Feb 2013
Posts: 330
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From: Northern Michigan
Year: 2001
Model: Cherokee
Engine: 4.0 V6
Well mine was before the head swap also. I wanted to do the swap regardless since I had the 0331 head but it wasn't cracked. I like the piece of mind.
Thread Starter
Seasoned Member
Joined: Feb 2013
Posts: 330
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From: Northern Michigan
Year: 2001
Model: Cherokee
Engine: 4.0 V6
Think I may have found my issue!!! This connection is at the ECU on the front drivers side fender. See the grey wire?. According to what I have found in my Haynes manual that grey/black stripe wire goes to the Crankshaft position sensor...which I replaced with a mopar one.
Who thinks this could cause the misfire? What's my best (correct) way of fixing this wire?
Thanks!
Who thinks this could cause the misfire? What's my best (correct) way of fixing this wire?
Thanks!
Thread Starter
Seasoned Member
Joined: Feb 2013
Posts: 330
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From: Northern Michigan
Year: 2001
Model: Cherokee
Engine: 4.0 V6
Alright so two days ago my CTS stopped working. My gauge wasn't working. So I put in a new sensor and it worked. Did some more repairs and it wouldn't go over 100 degrees. So I'm thinking I've got a bad wire somewhere since I've had the injector wires off multiple times. That will be checked tomorrow. I'm pulling p0118(CTS) and p0136 02 sensor circuit open. Which also runs off the same harness.
I fixed the wire at the ECU, not sure yet if that fixed my misfire but I was only pulling those two above codes now???
Did a compression test and was impressed with 168k. Below are pics of my plugs with about 267k on them. Cyl 1-6. Then dry compression readings 1-6.
I fixed the wire at the ECU, not sure yet if that fixed my misfire but I was only pulling those two above codes now???
Did a compression test and was impressed with 168k. Below are pics of my plugs with about 267k on them. Cyl 1-6. Then dry compression readings 1-6.




