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Help interpreting scan tool data

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Old 09-14-2005, 02:25 PM
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Default Help interpreting scan tool data

Can someone help in interpreting this scan tool data I collected this morning?

I have been following the topics posted by tverhein and jwikoff99 with interest as my '95 SLE has a similar sluggish acceleration problem. The fuel pressure is OK, the fuel filter, plugs and wires are fairly new, but early KR suspicions are confirmed by the scan tool that reveals 15 degrees boggin' me down. Can this degree of KR be caused by a ticking lifter?

I also noticed that the O2 sensor mv data changes so fast that in "view data" mode you can only see a blur of characters ranging from <100 all the way to 999. Is this normal? The value does not stay above 500.

This is my first use of the scan tool (Actron CP9110 w GM CP9111) and I need some help to get the most out of the data.

Thanks.

Here'* the not-so-pretty picture:

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Old 09-14-2005, 02:49 PM
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Holy geez. I only see KR at WOT, normally a few degrees, just got 17 under very specific conditions. You've got 15 at part throttle? And your knock counts are skyrocketing. I also have suspicions related to some lifter tick, but yours seems much more severe, whatever it is. Can you hear all that knock? I've actually heard knock, like a quick rattle, while scanning, and the knock sensor counts jumped dramatically at that time.
Old 09-14-2005, 03:36 PM
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Yeah, its ugly, ain't it? Nope, can't hear any detonation, and I am familiar with the sound. Used to "power tune" engines by accelerating up a steep hill and advancing spark until clatter, then backoff 'til quiet. You can hear that ^%$# lifter, but nothing else obvious. Makes me wonder what it could be. If you drive the car very gently, which I normally do, You never notice anything, but if you try to get on it, it is truly sick. My 1.6 liter Corolla could clean the SLE'* clock. It'* so wrong.
Old 09-14-2005, 03:40 PM
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Wow! That isn't pretty. Please report the problem if you find it.

I think the issue I'm having in this thread is related to KR:

http://www.bonnevilleclub.com/forum/...ic.php?t=39289

I can hear the rattling sound you described at WOT...or even at 1/2 throttle for that matter.

I'm intrigued...
Old 09-14-2005, 04:08 PM
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Bill, you won't hear knock or detonation, because the PCM retards timing when it 'hears' the first mild one. Prevents it from getting severe. The only way you could hear it is if your knock sensor had failed or was disconnected.

Taking a cursory look at your data, I don't see you running lean when you peak on knock. And from that data, it'* hard to associate the knock with a lifter or any other cause (call it FALSE knock with the lifter, rather than KNOCK).

Being an L36, this really surprises me, and ultimately I'd have to say an exhaust restriction somewhere should be the most likely culprit. If I'm correct (correct me if not), your rear EM is tubular, and the front is cast? Or is it the other way around? Carefully inspect the non-cast EM for cracks like I found on both of mine. That'* one possible cause. What'* the condition of the CAT? Do you have EM gaskets? If not, do you possibly have an exhaust leak there? What about your crossover and downpipe donuts?
Old 09-14-2005, 05:14 PM
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Is something wrong with Bill'* EGR system? Looks like a difference in those numbers.... maybe the combustion chamber temps are getting too high?



BTW, I generally don't know what I'm talking about
Old 09-14-2005, 05:18 PM
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Interesting...
Old 09-14-2005, 05:28 PM
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How are you guys exporting data from your CP9110?


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