Fuel trims and WOT/PE

[svede1212]

are long term fuel trims used in power enrichment at WOT?

[WS6FirebirdTA00]

If the FTC has a learned positive number, they are positive during WOT. They mean absolutely nothing though about WOT fueling, as it is not a "real" number.

[Rob's 73]

Are you saying then that the positive number isn't adding fuel during WOT? I thought that if it carried a positive number to WOT cells then it would also modify your WOT fueling but not retain it as a learned value. Just trying to keep this straight in my brain.

[5_Liter_Eater]

The way I understand it is the PCM takes the fuel trim value from the fuel trim cell you enter PE in and if that is positive it will add that much fuel to that PE run. So if you have a +5 LTFT in the cell you enter PE at then it will add 5% to your commanded PE AFR. IF the trim is negative it adds nothing and subrtracts nothing.

[WS6FirebirdTA00]

If it is positive, it is adding fuel at WOT.

Just because it is positive does not mean that is really needs that fuel. The system hits open loop and ignores the o2 sensors in PE conditions. I may be confusing you more than helping lol

[WS6FirebirdTA00]

The way I understand it is the PCM takes the fuel trim value from the fuel trim cell you enter PE in and if that is positive it will add that much fuel to that PE run. So if you have a +5 LTFT in the cell you enter PE at then it will add 5% to your commanded PE AFR. IF the trim is negative it adds nothing and subrtracts nothing.

yes

[vortech]

Is there any way to disable this?

[WS6FirebirdTA00]

Yes, disable LTFT's