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Speed density tuning always lean

Posted: Wed Jul 10, 2019 12:02 pm
by pedja1
Hello, I have a strange problem (or I might be doing something wrong), no matter how I change the fuel map, afr won't change. It is set to around 12.1 wot but it's always more than 13

Steps that I did:
- I flashed base sd map to my FN2, created some logs
- increase values in fuel map a bit to make it more rich
- flash the new map and again create some logs
- check the logs, same afr as before
In logs I check only wot part of the map, it's always running lean, I don't understand why

stft is 0 in wot, ltft is around 5, maybe this is the issue

Am I doing something wrong?

Re: Speed density tuning always lean

Posted: Wed Jul 10, 2019 1:45 pm
by KTuner
If you're just changing the WOT Enrichment targets and not getting your target, the base fuel tables likely need tweaking. You have to change the base Fuel tables so that targets are achieved in order for the ECU to target properly. It assumes the fuel tables are tuned for a perfect 14.7 in order for the enrichments to reach targets.

Re: Speed density tuning always lean

Posted: Wed Jul 10, 2019 1:57 pm
by pedja1
I was actually changing only targets in fuel table, I didn't touch wot table.

So if I understood correctly, fuel table needs to be tuned for 14.7, and then ecu uses that to target afr from wot table?

Edit: so if I don't want to cha ge wot targets, tweaking only fuel table would be enough to reach those wot targets, right?

Re: Speed density tuning always lean

Posted: Wed Jul 10, 2019 3:22 pm
by KTuner
Correct, you should be tweaking the fuel tables to change fuel output. There's 10 sets of fuel tables, for various cam angles and Low/High Cam, as outlined by the buttons and drop downs at the top left of the map.

Re: Speed density tuning always lean

Posted: Wed Jul 10, 2019 4:16 pm
by pedja1
Yes, that is what I did, I tweaked for all angles and low/high, and actual afr still won't match target afr, which is strange

I'll try to play around a bit more.
Thank you for clarifications

Re: Speed density tuning always lean

Posted: Wed Jul 10, 2019 5:47 pm
by KTuner
No problem.