If you add E85 to let me just say what is regular fuel here- E10.you can mess up the computer fuel map. According to a forum of which I am a member the alcohol content the computer thinks is in the tank can be reset with a scan tool. This person also said he knows people with flex fuel vehicle ,they never put E85 fuel in the vehicle. Just passing on what I have been told. Just a thought, since you have had many different grades of fuel in tank see if there is a way to test the sensor that tells computer the content of ethanol in tank.Never see flex fuel vehicles where I live.
Wow, what "forum" is that
vague UNsubstantiated info from? I'm trying to "hack" my way deeper into the obscure corners of my klugey mid-1990s OBD-1 AND OBD-2 scan tool, to find the actual Voltage Output of the ethanol sensor, but not there yet. Also need to research if my generation EEC-IV can output specific pulse-width data for the fuel injectors, or if it only derives that internally from the Fuel Trims. (Also not sure why that forum uses terms like "fuel map" or "ethanol in the TANK"... computer only knows--in REAL-TIME--the ethanol % in the line between the fuel filter and the fuel rails, and adjusts on-the-fly...)
However, I do see the computer adjust ignition-timing "BTDC" based on whether I'm running E85 or UNL87, so that sensor is doing
something...
(Even so-called E85 can be as low as 70% E, so no "mapping" possible, just SENSING...)
As far as "they never put E85 fuel in the vehicle", umm, WTActualFark? Why have a Flex-Fuel vehicle? While we don't enjoy the subsidized LOW E85 prices here on The East Coast that they do in the Midwest, it's still a low-cost way to scavenge ALL the water out of your system, AND clean the injectors, etc... Soon I will buy/rent a Borescope, and when I change out the schmancy "dual-platinum" plugs, I'll take a peak at my pistons and valves for carbon build-up.
(Will post pics if possible...)
(recent) True Story--
E85 saves the day: in April 2023 we had UNprecedented FLOODING here--Ft. Laud/Hollywood Int'l Airport CLOSED, Port Everglades FUEL Depot OUT OF ACTION! Peeps too young to remember the GAS LINES of 1973 got a big taste of those!... but not me--several stations were out of EVERYthing... EXCEPT E85! "Right this way sir, NO WAITING 4 U!" heh heh heh...
To paraphrase Blue Oyster Cult: "Don't fear the
Reaper Ethanol!" ... err, umm, IF you have V-VIN, lol...
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