What causes timing to jump while decelerating w/no throttle?
11-12-2004, 11:23 AM
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What causes timing to jump while decelerating w/no throttle? What cause that to happen? I thought the PCM was supposed to use the base table, but instead it will do that for fractions of a second, and then drop to some much lower number (10 degrees or more soemtimes), then jump back up. Pretty much, it does whatever it wants.
11-12-2004, 12:31 PM
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Are you sure this isnt DFCO. while the car decels in gear and hits DFCO timing will drop to 0 and injector pulse widths will also drop to zero. Once it crosses the lower threshold timing and fuel will resume
11-12-2004, 12:39 PM
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Originally Posted by HumpinSS
Are you sure this isnt DFCO. while the car decels in gear and hits DFCO timing will drop to 0 and injector pulse widths will also drop to zero. Once it crosses the lower threshold timing and fuel will resume
11-12-2004, 12:56 PM
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Well it takes a sec or two for it to enter so i doubt it is going in and out. A log will tell you better. It also goes in to OL when it does the DFCO thing, just an FYI
11-12-2004, 01:16 PM
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Originally Posted by HumpinSS
Well it takes a sec or two for it to enter so i doubt it is going in and out. A log will tell you better. It also goes in to OL when it does the DFCO thing, just an FYI
11-12-2004, 01:42 PM
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Originally Posted by HumpinSS
No because the trims stop learning in open loop mode. and will populate with 0's if i am understanding your question correctly
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11-13-2004, 08:20 AM
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Originally Posted by gameover
timing ramps down before the injector cutout, you may not be reaching the injector cutout before DFCO disables and timing kicks up again.
11-13-2004, 02:12 PM
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Aha. Now DCFO works again. I think I need to add a little more air in the throttle cracker tables now for my surging...it's a little better, but I still have a little bucking. I think it is better for the car to cruise a little than to buck like a bull...
