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hey there,
May be a silly question, but im wondering if there is a way to use my hptuners to reset faulty ethanol content calculations? The truck is a 2010 Gmc sierra, 4.8L v8. I have been having some hard starts in the winter, and have logged it to find that my ethanol content is reading 57% (not possible, i run 87 octane regular unleaded). I dont want to go to the dealer and absorb a 200$ bill.
Thanks in advance (=
Just disable it and it will all be fine.
Set the stoich valve to the whatever your zero % is, so 14.68. Set that to same for 0-100% alcohol content and then disable the virtual content sensor in the tune as well.
5FDP: Thanks alot for that. I have actually set the whole table to 14.6. I was going to see how it started up tomorrow. Where is the virtual content sensor in the tune if i could ask?
This sucks because im selling the truck, so i guess ill have to tell the new owner its disabled. We dont really have accessible e85 here anyways.
Engine > fuel > open closed loop > flex fuel. Then just set the virtual sensor from enable to disable.
Edit > view > advanced, if you can't find it.
Thank you very much sir!
5FDP - can you shed some light on how exactly the virtual sensor works?
It appears as though the virtual sensor would simply use the "default" value that is provided (that's how the little "help texts" read to me anyway), but setting the default value doesn't seem to actually change the value that the ECU is seeing as reported by the virtual sensor. This would be within the context of an LS7/E38.
Edit: I just realized that my issue might be that "flex fuel" may not set to "enabled" and thus the lookup routine may not be running. Even still, confirmation of the above behavior (or explanation if it's wrong) would be a huge help!
It's just taking the readings from the o2 sensors to guess at a change in alcohol content in the fuel. More alcohol content in the fuel will change how much oxygen the o2 sensors will see and the computer then figures out a guesstimation and spits out a number to use. They are not very accurate but they still work somewhat, not something to ever trust if you are serious about using E85 fuels all the time.
Yea, if I were going to run E85 I'd just set the car up to run E85 all the time like I did my drag car. I was looking for a quick way to get the ECU to dynamically recalc the stoich ratio for E0-E15 fuels, but after reading more (and your post to clear up the virtual sensor) that's not going to work out as I'd hoped.
I've looked at a couple of flex fuel vehicles and they seem to all have the virtual sensor, would I be okay to enable flex fuel on my truck and run e85 as long as I change the tables to match it?
Imo.. I would be comparing the part numbers for the injectors and fuel pump to a flex fuel truck. If they're not big enough you might not be able to handle the needed Volume for flex fuel
5FDP, for us GM 2000 3.8L SC guys, are we out of luck also? I was hoping to add an Ethanol sensor and have my computer / HP Tuners 3.x adjust the stoich ratio. I see now that there is not many values available to adjust unlike the v-8 guys. There is only one box for the target A/F ratio. Trying to think of a work around but I'm coming up blank. Any ideas? Thanks in advance.
You can just run E85 and adjust the fueling as needed with the MAF.
Changing the stoich ratio for E85 on a 3800 won't do anything, you also can't run a real sensor and have HPT use it.
Does just setting flex fuel to disabled work? Or do I need to change fuel sensor to sensor aswell?
Do you have a flex fuel sensor?Quote:
Originally Posted by Tkasprick
Got it all figured now