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View Full Version : COS3 and COS5 lean cruise PE Mode AFR error



ringram
August 13th, 2007, 07:23 AM
Hi, Ive posted about this a couple of times. Just sent Ross the tune and logs a few days back. Basically entering PE, or even just a richer than stoich afr causes the base AFR to go out of whack.

I recall seeing someone comment that it did the same for them on their holden when running lean cruise. (Same as me)

Just wondering who it was, and if they had found a work around for it.

Im pretty sure there is a little bug chewing away in the COS on Holdens anyway.

When returning to idle the AFR gets reset correctly.

5.7ute
August 13th, 2007, 11:04 AM
That was the issue I was having with COS5 in lean cruise. From what I could work out lean cruise would lock the AFR that was commanded once the lean cruise enablers had been met. This meant that if you commanded a richer mixture in the higher map cells & was under load when the time & speed enablers were met you would enter a locked enrichened mode that would not disable until you either hit PE or dropped below the enabler speed.
The only way I have got it to work is either keep the commanded AFR in B3647 to around 14.7 up to 80 kpa map & use pe if I want it enriched before this. Or to run a pseudo lean cruise with the B3647 table & leave lean cruise disabled.

ringram
August 16th, 2007, 07:11 PM
For me the commanded is almost a random number, sometimes rich, sometimes lean. :help:

5.7ute
August 16th, 2007, 07:25 PM
Sometimes the commanded AFR on mine was a bit strange as well. I put it down to interpolation between the cells in B3647 when lean cruise was activated. If I can find the logs I will post them up.