Quote:
Originally Posted by Tor
Thanks a lot again. I need a hint though as to why it's doing what it's doing, please.
I also opened pull 4 of log0006_9 where the OL fuelling was not corrected yet. It looks like this (delays not so prominent).
It's this log:
http://datazap.me/u/tor/tor-201-1-4-...?log=0&data=22
I also added AFR_Command to the selection of the pull you tried out:
So now I'm confused as to what I am looking for? If it's the delay, then it seems I caused it by changing OL? |
Are these done in the same gear? Obviously the delays change if the ramp is different speeds? The delay isn't the cause, my point was more of the case that you may need to change lower cells than the point of issue, so if the log is showing an issue at 4k you may be better adjusting those of 3.6-3.8k etc. Same with load if it's sweeping through cells quickly.
As for some help, have in mind this: If the fuel quantity remains the same but the AFR output goes rich, then the cylinder is getting less oxygen. If it goes lean, it's getting more oxygen but not all of this may be remaining in the cylinder depending on the overlap so may get a "false lean". There may be instances where EGR can mess with AFR readings, but this won't be the case on WOT so can be discarded. If you add fuel but it stays "lean" then there is a good chance that the intake charge is passing through the cylinder. What I've been trying to suggest is that you want the in cylinder AFR curve to be smooth and not swinging rich to lean. You want to repeat tests in the same gear etc but even then the AVCS can vary so you get differences pull to pull. So you want to look at changes of fuel quantity, the AVCS activity and the output AFR to get a good idea of what's going on. It's also why I treat the OL fuel table as just a fuel additive, because I'd much rather have my fuel delivery how I want it than needing my O2 sensor reading matching the AFR tables.
Quote:
Originally Posted by aagun
on ur map there are 44° of overlap duration at uncontrollable area 4K rpm. that's mean in FA20 that the intake and exhaust cams opened 2mm at same time. in that error will push the air from intake to exhaust Directly without burn it . that air is full charge of fuel . (thats why it coz jumping afr to rich at that dip)
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This
could explain why it goes lean after the rich dip, not why it reads rich. The sensor won't see the fuel in the exhaust. It's also highly unlikely at low RPM that there is enough vacuum to pull the charge straight through the cylinder, this is where the load logs will be of some use. Those logs show a dip in VE where these fluctuations are happening so it's not a sudden vacuum. Also, most of the fuel is provided by the DI. There is a much lower possibility (almost impossible?) of this being blown through the exhaust valves.
Quote:
Originally Posted by Tor
How can I calculate the overlap from the two tables? And wouldn't it be on purpose that the intake and exhaust valves are open at the same time to help scavanging?
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My AVCS tool
There's a formula in there you can add to your logs if you want to get the overlap into the log tools.