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Old 03-21-2014, 08:59 PM   #1
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Question MS2 pulling timing under load/throttle

Stock motor, No turbo, Reverant MS2.
Started recently nothing changed on the tune for months.

Thought it was bad gas or spark at first sounded like a bad miss at low rpm. Then I logged it and noticed the timing was pulling to 10 degrees when the issues was happenning.

Usually happens under 2k rpm but has gone higher occasionally. Not consistently though.

No idea what to check. Tune has been solid for a long time. Have not messed with anything tune or motor wise. And it runs like normal when it is not doing this.

Attached a short log. Highway driving.
Disregard Afr, it is wonky because a bad header to exhaust gasket. Not really running lean, been like that for months no previous issues.
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File Type: msl 2014-03-21_17-50-08.msl (177.1 KB, 117 views)
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Old 03-22-2014, 05:49 AM   #2
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Datalog doesn't show any signs of this issue. Can you capture it on a datalog?
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Old 03-22-2014, 08:02 PM   #3
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I guess I posted the wrong log. Was working from my phone.
Here is another log attached.

I thought I fixed the problem, re-calibrated TPS because I noticed it was reading from -0 though 102.
Drove great most of today, but issue is still there at low RPM.

I got a new gasket to fix the exhaust leak, so I should be able to get a clean AFR log tomorrow.
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File Type: msl 2014-03-19_06-11-44.msl (263.5 KB, 61 views)
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Old 03-24-2014, 12:39 AM   #4
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Post your MSQ.

Maybe it's erroneous data but it looks like your knock sensor is going ape-****. Try turning off the knock sensor and see if the problem goes away. Your timing is super conservative, so don't worry about hurting anything during this little test.
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Old 03-29-2014, 03:05 AM   #5
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I feel kinda stupid, but problem solved ( hopefully, no issue on cold start or hot start on the latest trip. )

Over the last week:
Turned off knock, still had a small miss. Then it got worse.

Bought some new plugs just to give it a shot, and number 4 plug was wet, (not coolant just water )
Dried it out, new plugs in, runs fine now even with knock sensor on.
My guess is misfire was causing the false knock readings and timing issue.

I checked that the plug wires were all connected, but never pulled out the wires and checked inside.

Moral of the story, check all the little things first, dry engine better after you clean it, and NGK plug wires will hold water in your motor for over a month if it somehow gets in.
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