Surging AFR's at idle S300v1

s300 and SManager software questions & answers
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abs0Lut
Posts: 4
Joined: Tue Feb 19, 2013 7:48 pm

Surging AFR's at idle S300v1

Post 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.
Attachments
shit idle 20secs.s3d
(93.19 KiB) Downloaded 63 times
scott 94 civic 3bar 550cc 282whp 226tq 13psi rev1 AF GAUGE SET.skl
(55.95 KiB) Downloaded 56 times
DaX
Posts: 654
Joined: Tue Mar 18, 2003 3:48 pm

Re: Surging AFR's at idle S300v1

Post 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.
abs0Lut
Posts: 4
Joined: Tue Feb 19, 2013 7:48 pm

Re: Surging AFR's at idle S300v1

Post 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
TTR
Posts: 106
Joined: Wed Mar 31, 2004 8:48 pm

Re: Surging AFR's at idle S300v1

Post 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.
abs0Lut
Posts: 4
Joined: Tue Feb 19, 2013 7:48 pm

Re: Surging AFR's at idle S300v1

Post 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.
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