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Surging AFR's at idle S300v1

Posted: Fri Jun 03, 2022 2:03 pm
by abs0Lut
Hey guys I was hoping someone could help me figure out why my tune at idle isn't smooth, the AFR gauge bounces between 13 and 15, it just doesn't sound right. I unfortunately don't get a response back from my tuner who is about 6 hours away so I thought I would try here. I will attach the data log and calibration. Thanks in advance.

Re: Surging AFR's at idle S300v1

Posted: Mon Jun 06, 2022 11:35 am
by DaX
I looked at your tune and datalog. Your battery voltage is low (12.3 - 12.7V), and if your dead times for the fuel injectors are off, this could cause fueling issues. I would find out why your voltage is down and double check your dead times are correct.

Re: Surging AFR's at idle S300v1

Posted: Thu Jun 23, 2022 2:11 pm
by abs0Lut
I had my alternator checked out and he said its putting out 14V. So... It isn't normal to drop in voltage when the cooling fan is on? I checked my dead times and they were slightly off so I changed those as well and I still get the slight surge in AFRs

Re: Surging AFR's at idle S300v1

Posted: Fri Jun 24, 2022 6:31 am
by TTR
What the alternator is out putting for voltage is not the same as what the ecu is seeing. Your log shows 12.4-12.6 volts. I would figure out why the ecu voltage is different from the vehicle voltage. Edit your breakpoints so you have a cell at your desired idle rpm to ensure it's not toggling between 2 different cells.

Re: Surging AFR's at idle S300v1

Posted: Fri Jun 24, 2022 2:08 pm
by abs0Lut
I watched it yesterday and it is reading the same as the battery, had my volt meter hooked up to make sure. That short datalog must have been from when the fan was on.