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Why would one bank run lean??

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Old 05-01-2006, 03:30 PM
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Default Why would one bank run lean??

I've noticed hesitation during part throttle acceleration. Looking at the wideband it appears that bank 2 is running lean (16-18+AFR) during this time. Here's the kicker...it only does this from 2000-2100 or so RPMs.

I'm thinking, either I'm losing fuel at that point or I'm getting an air leak. I swapped the injectors from side to side, to eliminate them. Can't figure out how an air leak could come and go.....ideas???
Old 05-01-2006, 04:36 PM
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The only thing I can think of, is the cam sensor. A few important functions of the cam sensor:

detect misfires

determine which half of the engine's firing sequence is currently in operation
Old 05-01-2006, 05:25 PM
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reminds me of a stupid line from 'gone in 60 seconds' - Angelina talkin about a guy riding his brakes and nick cage comments saying "sounds like the left bank is runnin lean.' Yea sorry I know that wasn't helpful..
Old 05-01-2006, 05:39 PM
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Originally Posted by Rescue Ranger
reminds me of a stupid line from 'gone in 60 seconds' - Angelina talkin about a guy riding his brakes and nick cage comments saying "sounds like the left bank is runnin lean.' Yea sorry I know that wasn't helpful..
Made me laugh though. At least I 'know' it is running lean, and not from listening to it
Old 05-01-2006, 05:44 PM
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get some starter fluid or carb cleaner and spray around the intake ports. I'm working to resolve a leaky #7 intake port gasket. Same symptoms you described.
Old 05-01-2006, 06:18 PM
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bad injector possible.
Old 05-01-2006, 06:24 PM
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Originally Posted by whiteLS1
bad injector possible.
Swapped injectors, side-to-side. Lean issue didn't follow the injectors, so I don't think it's that.

I'll check for a leaking intake gasket.
Old 05-01-2006, 08:21 PM
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bad 02 sensor?
Old 05-01-2006, 08:56 PM
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Originally Posted by JL ws-6
bad 02 sensor?
No, you can feel the hesitation when it leans out. Also, I double-checked my wideband with the dyno wideband when I was on the dyno recently.

I'm thinking it's a leak, but what leak can come and go at a specific RPM?
Old 05-01-2006, 08:59 PM
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Check your wiring harness for shorts, mine burnt and caused this.
Old 05-01-2006, 09:34 PM
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switch the coils and see if that changes where it is lean. that would be my next step
Old 05-01-2006, 09:40 PM
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Originally Posted by whiteLS1
switch the coils and see if that changes where it is lean. that would be my next step
hmm, hadn't thought of that. Pretty easy to do, I'll give it a shot. Thanks
Old 05-01-2006, 11:10 PM
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simple one, had a problem like yours, ended up cracking 2 of my plugs some how.
Old 05-14-2006, 07:10 PM
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OK, figured out that I've got a leak on the passenger side intake. Now the question is, how to fix it? I've already tried replacing the intake gaskets (both sides) with new ones. Re-checked the torque also. I'm wondering if I've somehow got a warped intake on that side.

BTW, it's a maggie (intake is part of the blower) so getting a new intake could be a costly proposition.



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