So out of no where my LTFT stopped showing.
I was working on idle and made some adjustment to the MAF Period table. I flashed the car and they never came back on.
I tried flashing the tune before the most recent flash and they still did not show up.
Any ideas?
LTFT are on in the tune.
Last edited by Blueprint; 06-15-2016 at 11:46 AM.
Every time you flash the car, it resets the LTFTs. Try driving the car(without flashing a tune) for a while and see if they start to populate.
Like explained above, long term fuel trims are long term. If you havent driven the car enough to build long term then only STFT will populate. After a flash you should drive the car and log a good long drive. I usually go on a 30 minute drive to get a good number of counts/cell
Still weird to me, car has been flashed hundreds of times over the years from bolt on car, to nitrous car, paxton car, to twin turbo car, twin turbo built motor. Never had this issue before LTFT show right away for me.
I drove the car for about 30min then let idle for 30 min. Still no LTFT.
Guess my only option is continue to drive since everything ive read is as you guys have stated they should eventually come online.
If you drove it for 30 minutes, the LTFTs should have enabled. Please post your log.
2012 Mustang GT with S/C
4Runner with S/C
Turbo/NOS Hayabusa - 320RWHP
Do you have flex fuel enabled? I just enabled mine yesterday and noticed that LTFT no longer logs, not in channels or on the tables. STFT1 and 2 seems to work fine though. It usually shows a zero for LTFT after a fresh flash, after some driving it would begin to populate, but now its just empty, no zero nothing. Wonder if it has to do with flex fuel being enabled
Last edited by Jn2; 06-17-2016 at 11:20 AM.
They eventually came online. Weird issue I guess. Have not had the issue again even after flashing multiple adjustments.
No I was not messing with the flex fuel.
I have the same issue , I was calibrating mustang gt 2016 Maf periods and no long term showing at idle .. But when I drove the car the long term can online again .. But when I stop the car and let it idle the long term stops again !!!!? Which drove me crazy ... I don't know if this is from how ford set it up or there is an issue !!?
It may be the scanner, assuming you've given the car time to populate the tables, connext your scanner, read vehicle, then go to vehicle tab and select "repolled for supported parameters" then record and you should have everything you need.
2013 Roush stage 3
Pypes cat delete
Tuned by me.
I had the same thing happen with enabling flex fuel. Is there a solution for this?Originally Posted by Jn2
This exact issue just happened for me as well. Did you ever get this sorted?
I never got it solved but I suspect it has to do with the factory Bosch wideband O2 sensors when Flex Fuel is enabled on a direct injected engine. For some reason the inferred fuel stoich is stuck on Actively Learning when Flex Fuel is enabled with a direct injected engine. After much digging, I found that the factory Flex Fuel Ford engines use NTK wideband O2 sensors from the factory including the Coyote Mustangs. Which explains why the Coyote Mustangs can just flip the switch for enabling Flex Fuel and be on their way. EcoBoost is a different story. Flex Fuel mode works for the most part as it adjusts the stoich to match your E85 blend, BUT it is stuck in actively learning and does not allow LTFT's to set, nor will the purge valve and other OBD2 checks complete. This means you will fail emissions inspection etc... I've asked around and some tuners claim they have a "flex" blend tune for EcoBoost Mustang but the way they describe it sounds like what I have done in the past and it is not true flex fuel mode.
Easiest way to tell the difference between the widebands is the NTK's have axial cut flutes (like your traditional O2 sensors) while Bosch has downward facing holes. My *guess* is the downward facing holes prevent/reduce carbon soot fouling from direct injection. But this has some effect on resolution perhaps.
I have not been able to find anyone knowledgeable enough on the wideband O2s to explain what differences there are between the NTK and Bosch widebands. I do notice that the Bosch widebands don't stabilize the inferred stoich enough to allow the PCM to Mature the fuel trim. The NTK widebands do that, hence why the Coyotes and factory Flex Fuel vehicles will switch to Mature within 13-16 minutes of driving.
I'm not the smartest tuner, so there could very well be a solution to enabling full flex fuel mode on a direct injected Ford but I haven't been able to find it. HPTuners doesn't know what I am talking about as they just look at tables and not for hidden parameters. If its not a physical wideband O2 issue, then there's some hidden parameter in the PCM. I even thought about retrofitting NTKs onto EcoBoost to see if that would work but I've about given up.
I'm not so sure it is the Flex Fuel mode that triggers it. Looking back at logs I recorded last year, I had LTFT/STFT working one day, adjusted some fueling and torque parameters (did not touch stoich or flex fuel settings), and my very next recorded log did not show LTFT/STFT.
I think this may be a reading issue? Something I would think HPTuners could lend a hand with...
I am unsure. I know someone else in this thread had the same issue I had related to enabling Flex Fuel. Are you running it in Flex Fuel mode? STFT should still be working either way. It's the LTFT that I had issues with.
I just experimented with the FFV settings yesterday. Was hoping to use the fuel trims to monitor changes, but noticed they weren't working. looked back at other logs and realize they haven't been working for some time. In fact, the log that I thought was working was only the STFT, but not LTFT. Subsequent logs don't have working STFT or LTFT's at all. I suppose i'll have to try and do a complete write back to stock and see what happens.
EDIT: I hope its just something I'm missing in VCM scanner. I don't really know my way around the software all that well.
Last edited by mgardiner1; 03-12-2022 at 11:27 AM.
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