Do you have a log scanned and saved? Just attach to your post, should have a place to add attachment
*edit*. If you aren?t seeing that, try using a PC or desktop version on your phone.
Do you have a log scanned and saved? Just attach to your post, should have a place to add attachment
*edit*. If you aren?t seeing that, try using a PC or desktop version on your phone.
Last edited by 4firemandan; 04-08-2021 at 11:23 AM.
Been looking around and havent seen much more info on the issues.
Would like to disable flexfuel and run reg e10 , as E85 is rare around here.
Buddies truck, will periodically climb the ethanol content to 85%.
Id like to be able to reset and relearn if possible delete it.
Any info on this? I am having issues after having Toyota replace my fuel pump and reset my ecu in early 2020Originally Posted by blackgnite@gmail.com
Hello. I running Tundra on natural gas and want to disable Flex Fuel.
Question 1:
I can remove FMP/VSV relay to make fuel pump works only in 'low' pressure mode.
Or i can jump wire FMP/VSV relay to ground to make fuel pump works only in 'high' pressure mode.
Dont know what mode better for that.
After i can disabel(fill by zero) all corrections in "Spark advance - Flex Fuel table".
sparks_ffv.PNG
Also can make "Injector const." and "Injector const. High" the same, depending of selected fuel pump pressure mode.
fuelinj.PNG
Is that things enough to disable FlexFuel corrections? Yes, ethanol percantage still calculating, but we remove all corrections methods?
Question 2:
Maybe HPTuners have any other option to disable FFV? Or planned to develop it? Maybe as it done in VF Tuner?
vft.PNG
Thank you!
Can you test these shutdown constants on your car?
I can give you User Defined Parameters.
Or send me your software, I can make it and you can check it on your car.
Last edited by ayashiko; 02-27-2023 at 09:31 AM.
I have a flex '13 Sequoia, Magnuson SC, Deaschwerks 300 pump, 5-0 750 injectors and RC-F throttle body. I bypassed the flex switching valve & am having issues with the truck thinking it has E85 although I have never used any.
I am HP tuned on a dyno & the issue persists. I cleared the ethanol, filled up and am at 2.7%. When this happens I get weird fuel trim issues & lose mpgs
Have you seen @4firemandan's posts?
https://forum.hptuners.com/showthrea...l=1#post624986
Yup, no joy
e30cabrio,Yup, no joy
It is normal for ethanol content and fuel trims to fluctuate after a fill up for the first several miles and minutes.
This bouncing around is when the truck/ecu is trying to figure out the eth content and it wil bounce around based on the instant (at that very moment) O2 sensor readings.
This distance and time it takes to lock in will vary, taking longer if the tune is less dialed in and shorter for tighter dialed in tunes.
You *Should* see the number stabilize after about 10 miles/10 minutes of driving (or less) unless you are getting greatly varied loads (like constant city stop and go... that will take longer). It also wants to see all ranges so going out on the highway may be great to find that data and seem locked but it will bounce around when you get back into stop and go for a little while.
After some time the ecu will get an idea of the averages and it will lock in an ethanol content and the eth number will stop moving and fuel trims will begin to normalize. THIS is what matters... the "Locked in" ethanol number.
Keep in mind that all gas (other than rec fuel) has up to 10 or even 15% ethanol depending on where you live.
If you are locking in at anything greater than 10% then your tune may be off. This is where most FFV Tunrdas struggle. Sometimes you can reset eth content and be good for a long while... it just depends on each individual tune and truck.
Reseting eth and FT
Resetting ethanol is of course also a PITA unless you have a Techstream. Fuel trims can be reset with a battery pull and stepping on the brakes for a few seconds to drain any charge.
To reset ethanol you can try this:
Reset the fuel trims at the pump before filling up.
Key on... let the ecu read the low fuel level...
Key off and fill up. (now with the freshly cleared fuel trims)
Once you fill up now the truck will be in eth learning mode starting with zero'd FTs and *should* correct any greatly skewed ethanol content because the O2 sensors will be reading from "0". It will take some driving to begin the learning but this is what i have found is the easiest way without a techstream.
If you DO have a techstream just clear FT and Eth and then fill up and drive to let it learn.... it should do the rest. If it's still locking in at abnormally high numbers from here... then the tune is probably very off.
Thank you. The tune was done on a dyno by an experienced tuner. He tried the steps in your other thread Wynnded quoted a few months ago.
I have had P0101 sporadically and poor MPGs so sent him a log that had the trims out of whack due to 30% eth although I'm filling with 91 so it should not be over 10.
I reset the eth in TS prior to filling up and verified 0%.
This fill up had about 40 mixed street and highway miles when I checked and it was over 2%. I have a 1000 Mike trip coming up to L.A. and would like to not get 10 on the freeway.
Thanks!
2% is no big deal. Even if the actual content were "0%" then the 2% eth reading would need like -0.7% total trims to correct the amount added for 2% eth.
As long as you have normal +/- 5 or even +/- 10% fuel trims (total LT + ST) then your economy should not be any different.
We see economy issues when the false ethanol reading is so high that the fuel trims can no longer overcome. I think our STFT max out at like 21 or 26%
What are your trims looking like with it locked in at 2% eth?
Last edited by 4firemandan; 08-28-2023 at 12:55 PM.
I didn't take a new read while it was at 2.x%. I just know my Tuner said it was way out when it was 30%. My concern is if I leave it alone I'll be back to 30% and a mess again & am hoping to get it to stop seeing nonexistent ethenol.
Here is a file when it was at 27%
A valid concern. The fact that it locked at 2% is good. That means its pretty close.
What you will likely see is an increase each time you fill up. You'll have to reset it once it gets up into the 30s.
The ECU has diff timing and fueling tables for 0-30% and 30+ so thats probably why you noticed it at 30%.
Unfortunately Toyota has a few odd ecu calibrations that dont automatically wipe the fuel trims when they see a fuel up in the FFV trucks. If thats the case, it can creep on you without a manual reset.
I'll be bringing the laptop with HPT & TS so I can keep track, the problem is like a water small leak you don't know until you get the big bill.
Guess I'll have to check the ethanol @ each fill-up.
lol
Thanks for your time!
Lol Great analogy!
You're welcome. Good luck!
p.s... if you have the ability to scan you can scan after the fill up and watch ethanol and LTFT's. The LTFT SHOULD zero out once it goes into learning mode and then change to a number once the ethanol locks in.
Otherwise you can just spot check it after about 15/20 minutes of driving to see where it ended up.
Great idea. I'll be filling up Thursday night, leaving for L.A. About 2am. I have 3/4 tank and won't be driving much before then. I'll run the scan on the freeway for 20 minutes or so and fill up again just before the CA border and get another 20 minutes.Thanks
I filled up yesterday, scanned & 20%. I cleared it & was at 0, I made a file that is in my other computer. I got 13mpg at an average of 70 in 2WD, not driving aggressively.
Edit, file uplaoded
Last edited by e30cabrio; 09-02-2023 at 12:21 PM.
Reply With Quote