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Post by sempar on Feb 14, 2020 16:12:07 GMT -6
I'm getting the above codes, but no misfire codes. Engine runs strong bnut has an unstable rolling idle due to lean conditions on both banks. I'm thinking it'a a vacuum leak somewhere, but so far I haven't been able to see or hear one. Anybody have any insights as to what it might be?
John
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tigger
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Post by tigger on Feb 14, 2020 16:20:45 GMT -6
Intake plenum boot?
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Post by Marc on Feb 15, 2020 9:08:51 GMT -6
Maybe the intake manifold gasket. That happened on my 2001 4.0 years ago.
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Post by sempar on Feb 15, 2020 15:36:46 GMT -6
Thanks guys, I'm thinking it might be one or the other as well. Will check the boot first, it's the easiest!
John
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Paulaurora
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Post by Paulaurora on Feb 16, 2020 14:01:54 GMT -6
90% boot:)
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Post by sempar on Feb 19, 2020 16:14:38 GMT -6
Thanks Paul,
I haven't taken the boot off yet, but I did do a quick visual inspection and didn't notice anything. I'll take it off and give it a thurough going over.
Thanks again,
John [/i]
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tigger
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Post by tigger on Feb 19, 2020 22:15:17 GMT -6
Just spray carb cleaner around the suspected area. If the idle changes, you've found your vacuum leak.
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Paulaurora
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Post by Paulaurora on Feb 20, 2020 15:50:35 GMT -6
^^^^ yep.. sometimes the boot screw on bottom can be not tight enough .
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Post by sempar on Feb 22, 2020 16:50:09 GMT -6
Took the boot and air cleaner assembly off; boot looks new, no cracks or obvious signs of deterioration. I paid special attention to the boot downstream of the MAF sensor. Re-seated the boot firmly onto the throttle body. I'll try and take it out this afternoon. Idle is fine when cold, but gets progressively worse as it it comes up to temperature.
John
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tigger
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Post by tigger on Feb 23, 2020 8:34:45 GMT -6
The "boot" that Paul and I are referring to is between the intake manifold and the back side of the throttle body. You have to remove the intake to get to it. It's sometimes called the intake coupler...  |
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Paulaurora
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Post by Paulaurora on Feb 23, 2020 13:21:44 GMT -6
Yep and even if you take it out it can be such tiny crack that you wont see it.but once you remove it you need to change other gaskets as well.
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Post by sempar on Feb 23, 2020 15:22:38 GMT -6
Oh great!
I thought you were referring to the rubber tube between the MAF and the TB! This is going to be fun... I can't even figure out how to remove the injector wire clips!! Arghh!! Must be getting old...
John
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tigger
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Post by tigger on Feb 24, 2020 12:06:52 GMT -6
It's not too bad, just take your time. Here's a pretty good walk-through...
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Post by sempar on Feb 24, 2020 17:31:17 GMT -6
tigger,
Thanks for the video, very helpful. Now I know how to disconnect the injector harness! Did it once before, but couldn't remember hqw I did it... I only have one grey plastic injector clip out of eight, wonder where the others went, somebody must have lost them in a previous owners service. I also know where my vacuum leak is now; the PCV hose to the intake is broken at the intake elbow, looks like new seals and gaskets to be ordered then I'll tackle it when the weather improves.
Thanks once again!
John
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tigger
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Post by tigger on Feb 25, 2020 12:54:17 GMT -6
No problem, glad to help!
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