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Unread 10-25-2011, 12:47 AM   #1
ljones628
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2 shops 5 mechanics and a 'star' tech..No clue why misfire

I have a 04 wrangler TJ-Unlimited. 4.0L 6I. 100340 miles

It is throwing misfire in 1 and 2 codes. Jeep and my mechanic can't figure out why it's misfiring...it usually only misfires in idle - but if it does out of idle its at about 55mph. The check engine light is on and last night it started flashing at me repetitive and the truck started running like it did with the failed lifter. I continued to accelerate (figuring either will total it out and i'm done with it or would cause another symptom to help figure it out). It went back to running its "normal" after couple mins. I have been dealing with this for bout 6 weeks now. It ran great for 1k miles after the lifter job...ANY IDEAS WILL BE GREAT!! :


List of what has been repaired so far:

Valve lifters (12) replaced

Heads checked(apparently not valves though)

Heads reurfaced

Thermostat

Thermostat gasket and housing

New plugs

New coil pack

Fuel injectors cleaned

Battery

Fluids changed


List of what's been checked:

Fuel pump, lines, injectors

Plugs

Coil pack

PCM

Compression

Timing

Can't find any leaks (intake/outake)

Can't remember rest off hand...

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Unread 10-25-2011, 01:03 AM   #2
lookmanohands
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I had a similar problem for the longest time and threw lots of new parts on as well. Rebuilt head, wires, plugs, injectors, cap and rotor. Misfire on cylinders 1 and 6 every time, and it would usually pop when I idled for a little while. It ended up being for me that the bolts on the underside of the intake/exhaust manifold were loose. I traced a slight whistle noise with a stethoscope to the underside of the intake and checked the bolts. They were loose enough to twist by hand. I think they had somehow worked loose over time after the head was replaced. Maybe like when they tell you to re-check the tightness of bolts when you replace suspension components. Worth a try.
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Unread 10-25-2011, 01:55 AM   #3
Heath
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Camshaft position sensor module?
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Unread 10-25-2011, 07:38 AM   #4
LJameson
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Did you put in a new cam with those lifters?
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Unread 10-25-2011, 09:20 AM   #5
chris142
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What kind of spark plugs were used? How was the head checked? Did they measyre the springs and ck them for being broken?
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Unread 10-25-2011, 09:29 AM   #6
Jerry Bransford
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I'm not pointing my fingers at the plugs yet but exactly what model spark plugs are you running and when were they replaced? Before or after the misfire started?
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Unread 10-25-2011, 01:26 PM   #7
herbiehind
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leak down test done?
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Unread 10-25-2011, 02:16 PM   #8
loaderopp
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I would move a spark plug and see if it moves the miss fire.....I had one bad plug out of 6 brand new.
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Unread 10-25-2011, 03:57 PM   #9
j_niko
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Cam lobe starting to wear down? That usually will cause an occasional backfire though.
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Unread 11-01-2011, 11:17 PM   #10
ljones628
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Yes cam been checked they said was good not new though.... spark plugs were in before lifter work done truck ran great for thousand miles after lifter work...the heads were resurfaced so the new gasgets would sit right I know they didn't check valves unknown on springs... can't find air leak..
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Unread 11-01-2011, 11:19 PM   #11
ljones628
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They put new cam sensor on and it still ran the same...

Jeep is now starting to run worse it sounds like a train in a sense with a hiss at times. It only does it in the mornings though. With or without warm up.
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Unread 11-01-2011, 11:23 PM   #12
Boodyrider
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Put in 6 new double platinum plugs, just try it.
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Unread 11-01-2011, 11:23 PM   #13
ColoradoCole
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what do you mean by hiss ?
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Unread 11-01-2011, 11:25 PM   #14
ljones628
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Tension pulley seems loose to me....the bolt on left side closest to firewall on top side the nut is not even touching the tip of valve cover I know certain order of tightening but can I redo that one without all the others? Can't hear air or not due to engine bouncing and loud chug sound
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Unread 11-01-2011, 11:29 PM   #15
ljones628
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I'll get plugs and try it

Hiss like have a air leak on right side but can't find it
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