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Old 03-05-2011, 06:03 PM   #11
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Look close at your graph. I'm seeing up to 13* of KR, and that'* BAD Your engine is acting up because of this. Now you need to find why your getting this level of KR, you really want that at zero at all times. I see 3 cases of very high KR and all are with RPMs over 2k. If that'* true KR you risk damaging the engine. But it can also be false KR. So, here'* what I want you to add to your scan. Keep KR, timing, RPM LTFT and add current gear and throttle position.

Have you changed anything on the engine, exhaust, mounts, etc.
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Old 03-05-2011, 06:12 PM   #12
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Ok, let me see what I can find in this software...

PS.. That'* about how violent it chugs when it hesitates. The transmission mount on the front drivers side was recently replaced and I can hear it squeaking when the chugging and hesitating is going on.
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Old 03-05-2011, 06:20 PM   #13
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Your going to want to look things over close. Look for metal on metal contact. Did this start after that mount was changed?
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Old 03-05-2011, 07:00 PM   #14
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No, the mount was one of the things the dealership changed in their $1500 fix that didn't fix the problem.

What was done prior to this happening was my mechanic had just did the 100K go over. He said he changed the plugs, wires, serp belt and tranny fluid. My UIM was leaking coolant or something so the receipt said he got a "plenum gasket kit". It ran beautiful for about 3 or 4 days when I got it back from him then this started happening. The temp was about -10 that day. Today is warm (47) so I wonder if the working good has to do with the weather???

Since it'* running comparatively good today and the only time I could get it to chug was wen I kicked it into passing gear. Unfortunately it didn't fail that every time I got it to chug someone moving slow got in front of me and I had to back off.

I couldn't figure out how to get the current gear PID to register but what I'm doing and letting the car coast until it settles into a gear then I go WOT which kicks it into passing gear and is the only time its messing up today. It doesn't do it 100% of the time. More like 30% today.

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Old 03-05-2011, 07:43 PM   #15
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Check teh fuel pressure when driving and at WOT. I wonder if your going lean.
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Old 03-05-2011, 08:19 PM   #16
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Not following what you mean??? The fuel air ratio is red in the bottom graph. Is there another fuel measurement? I can't get the rail pressure to show but are you suggesting a pressure gauge hooked to the regulator feeding into the car so I can read it going down the street?
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Old 03-05-2011, 08:21 PM   #17
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And something else I just noticed, the speed control light blinks when this is going on or during heavy acceleration.
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Old 03-05-2011, 09:33 PM   #18
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From the looks of it, your commanded AFR is sitting around 14.7:1 when you did a WOT. For a NA engine this should be closer to 11:1. You can see on one of my scans my AFR drops when I do a WOT. Yours sits at 14.7:1

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Old 03-05-2011, 10:56 PM   #19
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What stands out to me about your graph and how steady your advance sits until you open the throttle then it moves almost in reverse sync to your throttle position. In fact all of your readings with the exception of O2 sit steady until you open the throttle.

Something I noticed studying my graphs, I do tend to get knock advanced each time I go WOT whether the motor shudders or not. Either I have another bad motor mount or perhaps it'* the wires to my knock sensor that are having a fit.
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Old 03-05-2011, 11:01 PM   #20
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Your engine is not boosted correct?

I would suggest getting a fuel pressure tester and checking the fuel pressure. I have a feeling your pressure might be dropping off at WOT causing you to go very lean. Can you scan your O2 sensor? That would give you an idea of what is going on. You should see the O2 around 920 at WOT You can see this in my scan, the O2s go from cycling between rich and lean and then holds steady at rich.
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