Why would so much timing be pulled without knock counts?
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Joined: Oct 2002
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From: Oklahoma City, OK
Car: 92 Z28
Engine: 357 TPI (L98)
Transmission: 700R4
Why would so much timing be pulled without knock counts?
I need the more experienced to help me understand something.
I was getting a terrible shudder in 4th gear with lockup and thought the TCC was going out, so I disabled it and ran again, and found that the engine is really struggling in that range and fluttering about, which was probably CAUSING the TCC to engage and disengage rapidly, so I looked into the ALDL stream for clues.
I'll post a link to the log below, but first I'd like to comment a bit, I'm getting a code 43 when I run the car, but I've had that before and it was false and went away. I go through the flowchart in the Helms manual, but the only thing I conclude is it is intermittent.
What really confuses me is that a lot of timing is being pulled out in the region when the engine is struggling, yet there is no knock present. Why would the ECM do this? In fact, a lot of weird things happen in that range....the retard goes way up, the injector pulse width goes way up, as does MAP pressure, BLM's, and other things. I'm sure you'll be able to see it plainly from the log....what do you think?
Will any of you guys help me figure this out?
Here it is (Moates .csv format)
I was getting a terrible shudder in 4th gear with lockup and thought the TCC was going out, so I disabled it and ran again, and found that the engine is really struggling in that range and fluttering about, which was probably CAUSING the TCC to engage and disengage rapidly, so I looked into the ALDL stream for clues.
I'll post a link to the log below, but first I'd like to comment a bit, I'm getting a code 43 when I run the car, but I've had that before and it was false and went away. I go through the flowchart in the Helms manual, but the only thing I conclude is it is intermittent.
What really confuses me is that a lot of timing is being pulled out in the region when the engine is struggling, yet there is no knock present. Why would the ECM do this? In fact, a lot of weird things happen in that range....the retard goes way up, the injector pulse width goes way up, as does MAP pressure, BLM's, and other things. I'm sure you'll be able to see it plainly from the log....what do you think?
Will any of you guys help me figure this out?
Here it is (Moates .csv format)
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From: Moorestown, NJ
Car: 88 Camaro SC
Engine: SFI'd 350
Transmission: TKO 500
Axle/Gears: 9-bolt w/ 3.23's
If it constantly throws a code 43 then the computer is going to set max retard at all times after the code is set (SES on). Fix that first and see if the problem persists. If there is a problem with the actual ks or its circuity then no knock counts may be reported through the ALDL.
Last edited by dimented24x7; Jul 22, 2004 at 08:51 AM.
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From: Midwest City, OK
Jamesbob,
I see we're pretty close to each other, I'm in OKC just north of Moore by Tinker.
The code 43 is something I would investigate further. As I understand the '730 every once in a while it will send a message down to the KS I guess to say "hello how are you?". If the KS is acting a bit funky it could cause you too pull timing but I would venture to say that you might see knock counts as well, not just KR in the datastream.
It is also possible that your ESC module is flaky and may also be causing the timing to be pulled without triggering the KS.
Both are very likely suspects.
-Brian P
89 IROC-Z LT1 intake
I see we're pretty close to each other, I'm in OKC just north of Moore by Tinker.
The code 43 is something I would investigate further. As I understand the '730 every once in a while it will send a message down to the KS I guess to say "hello how are you?". If the KS is acting a bit funky it could cause you too pull timing but I would venture to say that you might see knock counts as well, not just KR in the datastream.
It is also possible that your ESC module is flaky and may also be causing the timing to be pulled without triggering the KS.
Both are very likely suspects.
-Brian P
89 IROC-Z LT1 intake
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