Thread: High Long Term Fuel Trims - why?

O2 2x1 is reading much higher than the other, is there a reason for it? Your stft on that bank is reflecting such.

I'm not a guru so feel free to put me in line if I have stated something silly!

Nah Keithy, the O2s flick from 0.0-0.9 every second or so, and should do. The snapshot in time isnt important on that particular guage. The min and max values over time is important though, for this investigation (I think)

The O2 sensors have a heating element. Perhaps the element of the lower reading one is not operating as it should.

I'd suggest a steady 25km (each way!) run down the nearby freeway and then recheck the numbers. A 20km one-way trip is probably the bare minimum to stabilise the system, even in SEQ balmy weather!

You reset the adaptive fuel values to zero with a Nanocom or Faultmate... can you do the same with the Torque app... start the re-learn process?

BTW is the screen shot looks great! is it from your phone or a Tablet?

Originally Posted by Hoges

The O2 sensors have a heating element. Perhaps the element of the lower reading one is not operating as it should.

I'd suggest a steady 25km (each way!) run down the nearby freeway and then recheck the numbers. A 20km one-way trip is probably the bare minimum to stabilise the system, even in SEQ balmy weather!

You reset the adaptive fuel values to zero with a Nanocom or Faultmate... can you do the same with the Torque app... start the re-learn process?

BTW is the screen shot looks great! is it from your phone or a Tablet?

The O2s heating elements throw codes if it cant pass the ECU tests I believe. The fact that its bas on both banks suggests to me intake air leak or MAF, but the intake is pretty solid, and I am sick of changing MAFs!

The LTFTs have been that way for a couple of weeks now, even after 100km trips to Sunny coast and back.

I have reset adaptive values with FaultMate, the LTFTs end up back where they are.

Screen shot is from Torque on android, listening to a Kiwi OBD bluetooth dongle - the Kiwi device is good, but Torque can only reset fault codes, not reset adaptive values.

I'm not quite up with O2 sensors and how they operate, so I may be barking up the wrong tree.

Your water temp on the pic being 85 is too cold. I know the GEMS system starts richening the mixture up at 87 to get the motor back to temperature.
Does it heat up to where it should be?

Very good question Benji, no, it doesnt. That is the temp that it runs at since putting in a new water pump and radiator last month. It gets up to that temp quickly though, which suggests the thermostat is closing and opening?

I am suspicious about the low value for the MAF. I believe MAFs fail "low" when they fail so can someone please run Torque across an OBD adaptor for a longish trip and tell me what their MAF reads as a low value?

Once I can confirm that low value (I am getting 5-6, and I think from memory it should be 9 or 12) is ok, I will look into that temp suggestion.

Hi Glen

I have a spare MAF if you want to try it for a while.
Ken

Originally Posted by Fitzy2011

Hi Glen
I have a spare MAF if you want to try it for a while.
Ken

Wow, great idea - why didnt I think of that?!

Tell you what, if I can borrow it for a few days, I will commit to recording min and max values for various MAFs under various temp conditions and record them here for posterity. We have a few threads around with voltages, but it will be much easier and more useful in the future with grams/sec over commonly available smartphone technology.