5.3 Z motor flex fuel delete question.

[vettemakesemwet]

Title says it all. Been playing with a tune from the repository for practice as I want to disable flex fuel, remove the sensor, and put a fuel pipe into the lines. Want to make it like flex fuel was never there. On the general tab setting stoich afr to 14.68100 all across. Open loop tab set alcohol eq ratio to same as gas eq ratio, whole table. On the flex fuel tab, turning off flex fuel master, set default alc % to 15, min hz to 0, and max to 1 for sensor fail. Disabled the DTCs for flex fuel sensor.

Question is, am I going too far after just turning off flex fuel master switch? I modeled it after my personal 05 sierra 5.3 non flex fuel T motor, with the only extra being the flex fuel sensor fail parameters adjustment. My thinking is if e85 is never run, and most we'll get at pumps is e-15/85% gas, and if for some reason with the sensor disconnected and the PCM sees any frequency on that disconnected connector, it will default to a 15% alcohol content and would run the fuel table/stoich that is equal to the gas only one. Don't see how this could cause a problem, but not 100% sure it won't go FUBAR either.

Couldn't find that last bit in the search i did. Any takers on an answer?

Thanks in advance.

[5FDP]

Just setting the stoich to 14.68 would have made the sensor useless, so the rest is technically overkill.

Just leave the sensor in the fuel line, no reason to spend money on stuff that can just stay there as it harms nothing. Disable the master switch and turn off the DTC's. Kick back and forget it was ever there.

[vettemakesemwet]

The pipe would only actually be used if the sensor was physically leaking, but was in the vision for the full setup if needed. Have a few friends I would love to help out for the cost of the license and some mountain dew. Thought I was going slightly overboard in the tune, lol. E85 has its place, just not in my tank. That's why I bought a non flex 5.3 truck. Thanks for the info.

[5FDP]

I went the other way lol. I added the sensor to my newer truck that never came equipped with it. Mainly for the power bump when using it and the cost/mile doesn't change for me in the summer time as I only drive 8 miles a day so mpg is the same.

[vettemakesemwet]

Not much need for more power in the grocery getter/soccer mom crowd. Just beats paying ~$1K for a sensor+labor+diag when they NEVER use the e85 in the first place. Tossed around the idea of going E85 in my vette when I go FI on it, but not sure given lack of places that sell it here. My tinkering nature keeps telling me to make my own special blend....muahahahaha

[kingtal0n]

my car is so old I'm afraid if I put E85 in the tank it will dissolve

[Boost]

my car is so old I'm afraid if I put E85 in the tank it will dissolve

My '01 with 100k+ miles is Flex fuel capable from the factory (5.3 Z motor). But I am pretty sure it never ran ethanol all it's long life, most likely crap 87 as it was in rough shape when we got it. Now that it's purely on E85, I wonder if the gunk from that tank and everywhere is being dissolved and sent to clog pump pickup/filter/injector tips. (?)