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popping a backfiring after head swap??

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Old Nov 26, 2011 | 02:40 PM
  #1  
miglia-spyder's Avatar
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From: Grand Rapids, Michigan
Year: 2000
Model: Cherokee
Engine: 4.0
Default popping a backfiring after head swap??

I swapped out my cracked head with a brand new one. Everything went great, and it ran better than it usually does for about a week ago. Well yesterday i went the gas station and left it running outside. It was running really rough and popping and backfiring. I thought it might be a heat soak issue, but the motor wasnt overheating at all. Well anyways now even when its cold it runs like complete crap...

I pulled the valve cover to find a couple loose rocker arms. But nothing crazy. So ill order a rocker arm kit.

I havent had the CEL checked yet (Auto Store isnt open)

Any ideas?
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Old Nov 26, 2011 | 02:41 PM
  #2  
The Rooster's Avatar
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From: Bergen County, New Jersey U.S.A.
Year: 1990 Laredo
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Engine: 4.0 Inline 6 Renix
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I would check your timing... and did you get gas at said gas station... might be bad gas... but 1st I would see what the light is
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Old Nov 26, 2011 | 02:56 PM
  #3  
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From: Grand Rapids, Michigan
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I didnt check the timing. I didnt get gas...Just snacks and beer. haha

I also noticed that it has short spurts of randomly running perfectly. (like 10 secs)
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Old Nov 27, 2011 | 01:39 AM
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Sounds like a burnt valve.
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Old Nov 27, 2011 | 05:29 AM
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From: Prescott, Az
Year: 1990
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Rocker arms are loose? How about bent pushrods?
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Old Nov 27, 2011 | 11:57 AM
  #6  
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Originally Posted by Firestorm500
Sounds like a burnt valve.
Originally Posted by cruiser54
Rocker arms are loose? How about bent pushrods?
NOt what i was hoping to hear with a brand new head

Fukc
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Old Nov 27, 2011 | 11:59 AM
  #7  
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From: Broward County Fl.
Year: 1989 xj sport 2dr
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Engine: 12 hole bosch Injectors
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possible sticking or collapsed lifters
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Old Nov 27, 2011 | 03:02 PM
  #8  
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That's what I'm thinking! I put some seafoam in the both the crankcase and the intake manifold. It idles now without ticking or missing. But as soon as a bring it up above 2000 rpm it will tick and run bad again. I can't really drive it the way it is because it runs so bad.

Last edited by miglia-spyder; Nov 27, 2011 at 03:05 PM.
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Old Nov 27, 2011 | 03:03 PM
  #9  
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Not I s I'm hoping te seafoam

What does that ^^ mean?
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Old Nov 27, 2011 | 03:05 PM
  #10  
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From: Grand Rapids, Michigan
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The Cherokeeforum app doesn't always work the best. My bad
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Old Nov 28, 2011 | 08:41 AM
  #11  
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From: Grand Rapids, Michigan
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Im pretty sure that its a sticking lifter... If im correct once the cam starts hitting the lifter at a certain speed the Lifter locks up causing one of the valves to not open fully. Which is causing my backfiring and popping.

Does that sound about right?

On the bright side, I did get an OB2 code reader today and will check the codes after work.
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Old Nov 28, 2011 | 11:31 AM
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Did you make sure when you put it back together you put the lifters/pushrods,etc back in the same order as they came out
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Old Nov 28, 2011 | 12:08 PM
  #13  
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Originally Posted by 2000xj34
Did you make sure when you put it back together you put the lifters/pushrods,etc back in the same order as they came out
Yes. I had each set organized as I took them off.
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