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af changes when switching from closed to open loop
Posted: Sun Nov 29, 2009 2:06 pm
i have a problem car that i'm helping with. tunes fine on open loop but goes dead rich immediately when closed loop box is checked. i set all compensation trims to 0 just to try with no difference. timing does not change appreciably. any ideas before i shoot the ecu and start over?
Posted: Sun Nov 29, 2009 6:28 pm
Check your target voltage under parameters-closed loop tab. Make sure that it is in accordance with your voltage offset which easiest by bringing up the display tab while you are datalogging, create a wideband AFR value (right clicking the main field click new value) and also create an O2 voltage value...get your AFR where you want it then look at the O2 voltage and use that number as your target voltage .......if thats all good, check to make sure the wideband signal wire isn't installed into the stock O2 sensor input in the ECU.
Posted: Sun Nov 29, 2009 7:17 pm
thank you for the reply, but that's covered. target voltage is .51V and when the closed loop is engaged and the fuel goes rich there is no short or long term trim indicated. it continues to do this even with the wbo2 wire removed from the ecm connector. even started a new rom from scratch and just copied pertenent maps with the same result. going crazy.... i've been tuning hd for years and this is my first stumper that wasn't code-caused.
Posted: Sun Nov 29, 2009 8:12 pm
hmm well I would say post your datalog and cal, because that is a stumper without seeing all your sensor information and settings. I'm sure spunkster or hondata has seen this alot...