bpaspi

O2 sensor values are not involved during open loop.
Please read my post again. I know my english is not native, but I try my best.
The LTFT Tables are not feed by the O2 sensor! It is feed by the STFT values.

spectacle

LTFT is not applied in WOT. Sorry but you've been given incorrect data. Dunno who you were talking to at Hondata: http://hondata.com/forum/viewtopic.php?t=11528

bpaspi

[QUOTE]If changes are made to the engine which alter the amount of fuel that is delivered (bigger injectors, increased fuel pressure or altering the air temperature sensor voltage) the ECU will compensate the best it can using the long term adjustment.

spectacle

That's wrong.

rog06s2k

No worries bpapsi, English is not my first language either.
I think the only time the LTFT are used in open loop is during the starting strategy, ie; -4.7% of the last LTFT recorded in NVM, for the first xx seconds then engage closed loop...
However you pick my curiosity and I'm searching deeper...
Cheers

rog06s2k

Well after a couple of hours of reading I have to agree with Bpaspi.
- Disable the close loop before PE tuning (WOT)=open loop
- then enable close loop and ensure that your part throttle LTFT's are close to 0 or negative (rich) in part throttle tuning

LTFT's do play a part in the PE map, if your LTFT's are consistently on the positive (lean) side in closed loop, when jumping to PE that correction factor will be applied to the fuel map.
During starting the ECU is in open loop until the monitoring is ready (close loop) do the LTFT's play a part, I don't know/not sure that is for another day.
Now I need a beer...
Cheers

H22toF20

Interesting. I'm kind of curious now myself.

spectacle

...Which is fed by o2 sensor values. Think about what you're saying. You're saying that the WOT fuel map is being direct affected by the partial throttle corrections made under a lot smaller of a load with totally different fuel demands. That makes absolutely no sense and its not how it works.

NO LONG TERM OR SHORT TERM FUEL ADJUSTMENTS ARE MADE in OPEN LOOP. Period.

spectacle

Where the hell are you getting this info from?

LTFT doesn't apply in cold start. Its open loop where no corrections are made.

Trevorlj

It's not impossible for LTFT's to affect full throttle operation. I'm not sure about Honda but I can tell you GM & Mitsu engineers usually allow LTFT's to add fuel at WOT.

IE if the computers LTFT is at +3.3% it will also add that same 3.3% to the fuel schedule (across the board) at full throttle.

As far as taking fuel out at WOT with LTFT goes Mitsu allows it but GM usually doesn't (playing it safe there).

To be clear...there is no real time tuning going on at full throttle in systems with narrowband O2's. What happens on these is when you go full throttle all fuel trims are immediately "frozen" and whatever is the last known long term is applied to open loop fuel schedule. As soon as you go back to cruising and into closed loop the trims are "unfrozen."