Why is my timing retarded?
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Joined: Nov 2002
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From: Berkeley, California
Why is my timing retarded? At WOT, my maximum spark advance above 5000 rpm is 19 degrees. My high octane table calls for 22 degrees. Low octane table calls for 15 or 16 degrees. I have zero knock retard and both ECT and IAT are in areas that subtact zero. I don’t have traction control. No trouble codes (DTCs). Any ideas?
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Joined: Nov 2004
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have you got both spark tables running? (ie custom os if in SD or MAF)if so check what your knock learn factor is, if its anything less than 1 then it will pick a number between the lo and hi tables depending on how low the KLF is
Originally Posted by SikHabibBroCuz
have you got both spark tables running? (ie custom os if in SD or MAF)if so check what your knock learn factor is, if its anything less than 1 then it will pick a number between the lo and hi tables depending on how low the KLF is
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Thread Starter
10 Second Club
Joined: Nov 2002
Posts: 1,471
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From: Berkeley, California
The proximate cause of my limp timing was the Knock Learn Factor. The ultimate cause was me disabling the MAF during SD tuning which sets the KLF to zero. This appears to be the method the PCM uses to select the low octane spark table in case of MAF failure. The PCM does not fully revert to the high octane table until the KLF returns to a value of 1.0 which it does slowly. WOT timing has recovered to 21.5 degrees as the KLF has increased from 0.69 when I first checked, to 0.91 after 15-20 minutes of driving around. Thanks to all who chimed in – I learned some good stuff.
-Gary
-Gary
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Verdad Gallardo Thread Starter
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Joined: Nov 2002
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From: Berkeley, California
Originally Posted by PlatnumStatuz
Hey Gary, wussup looks like you've been busy from the looks of your sig since last time I saw your car at Sears Point. I'm doing a h/c swap on my camaro right now.