AFR lean at WOT

FlashPro questions & answers specific to the 2007-2012 Acura RDX
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2010rdx
Posts: 2
Joined: Fri Feb 24, 2017 11:49 pm

AFR lean at WOT

Post by 2010rdx » Sat Feb 25, 2017 12:29 am

While looking at a datalog (attached) that I made a few days after loading the tune that came with the FlashPro, I noticed a couple of things that were concerning, although that may just be due to my ignorance. First, the AFR at WOT is around 0.75 points leaner than commanded (~12.75 vs ~11.98). Second, there is a spike to 15.67 AFR during the 1-2 shift. Should these be expected?

Also, after an hour of driving, the knock count on cylinder 2 was 9 with a total knock count of 13. Is it worth trying to trim the timing to eliminate this or is the count low enough to not be a concern?

Thanks for your time.
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WOT_1-2.fpdl
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TDM
Posts: 22
Joined: Wed Jan 11, 2017 6:21 pm

Re: AFR lean at WOT

Post by TDM » Tue Feb 28, 2017 8:58 pm

The "commanded" AFR at WOT of 11.98 is from the WOT lambda adjustment table and the 12.75 AFR is the resulting AFR from whatever the programmed fueling is at that manifold pressure. There is no closed-loop feedback (attempt to achieve the "commanded" AFR) in WOT like there is in closed loop operation. In other words, if the AFR is 6% lean in open loop, the fueling needs to be increased 6% at that location in the fuel table. I wouldn't be too concerned with the 12.75 AFR at WOT unless you have some track days coming up.

At your gear change, the fueling drops momentarily even though you have the throttle on the floor (see how INJ drops from 16ms to about 8ms?) this is what causes the momentary increase in AFR a few tenths of a second later. This is normal.

rdxturbo
Posts: 5
Joined: Sat Feb 23, 2019 6:48 pm

Re: AFR lean at WOT

Post by rdxturbo » Sat Feb 23, 2019 7:03 pm

I sometimes get a hiccup during the gear 1-2 shift. This can happen during WOT or partial throttle, but only between gears 1-2. When the hiccup happens, I hear a pop coming from the engine and the power cuts out for a split second. This has happened when I got my ECU reflashed by Hondata back then, and it still happens now after I got it tuned by Church. On all the RDXs I've owned. I was able to datalog when it happens. Seems like the injectors cut out and the A/F spikes to 16:36. (Attached datalog, at time 04:21)

Also, I'm trying to eliminate my high load, low RPM knocks by adjusting ignition when the Knock Control is high (as you guys suggested in another thread). When reviewing my datalogs, I noticed that my load columns on the index table only go up to 7 and sometimes the load meter goes off the chart. Is this normal? (Attached pic)

Thanks for your time.
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huccup at time 04,21.fpdl
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rdxturbo
Posts: 5
Joined: Sat Feb 23, 2019 6:48 pm

Re: AFR lean at WOT

Post by rdxturbo » Mon Feb 25, 2019 5:01 pm

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