Weird behavior with E85.

Hello everyone I was curious is this normal for E85 ?? Anyway up from my house a gas station been offering E85 for a few months now I was curious how my 2010 Expedition EL would run on it since it’s flex fuel Vehicle so I filled up on a very empty tank I filled it with E85 then I noticed stopped at a light the RPM’s were dropping then normal like it was going to stall out kept driving it went away .

Then the next cool morning I tried to start it seem like it was struggling to start the engine quit trying I had to try to start again then it started low RPM’s once warm went away I went to work that night the next morning it refused to start again at first then started very very rough sounded like a Metal can under the hood turned it off restarted it was fine but it was throwing too lean codes .

Seems like it better now but think this will be the last time I put E85 in my expedition it didn’t like it at all my guess the computer was trying to relearn for the new fuel type ? That was definitely a weird experience...

Hmm, I'm unsure if it's the E85 but I could be wrong. The only difference I noticed on a drive across several states in a different truck (Ram 1500 quad cab) I also filled up with E85 a few times and noticed a little less power which I expected.

Hope it's just the gas though.

Jon1985 said:

Hello everyone I was curious is this normal for E85 ?? Anyway up from my house a gas station been offering E85 for a few months now I was curious how my 2010 Expedition EL would run on it since it’s flex fuel Vehicle so I filled up on a very empty tank I filled it with E85 then I noticed stopped at a light the RPM’s were dropping then normal like it was going to stall out kept driving it went away .

Then the next cool morning I tried to start it seem like it was struggling to start the engine quit trying I had to try to start again then it started low RPM’s once warm went away I went to work that night the next morning it refused to start again at first then started very very rough sounded like a Metal can under the hood turned it off restarted it was fine but it was throwing too lean codes .

Seems like it better now but think this will be the last time I put E85 in my expedition it didn’t like it at all my guess the computer was trying to relearn for the new fuel type ? That was definitely a weird experience...

Click to expand...

I've heard E85 will dissolve gunk in the fuel filter. That's might have something to do with it.

Lean codes and a fuel that requires more volume compared to gasoline aren't generally good. I'm almost wondering if there is an underlying condition. Perhaps partially clogged fuel filter? Failing fuel pump or one not switching to high speed mode when e85 is detected? Clogged injector? If it goes away once you go back to normal pump gas I'd almost bet on something to do with fuel delivery.

Switching fuels would cause things to learn a bit but being its designed for E85, once it realized the fuel was in based on the sensor they have it should alter timing and such to accommodate. If a sensor were bad it could cause the truck to think its running something completely different and maybe cause a code. Do you have a scanner than can show fuel trims? If it thinks its lean and is dumping too much fuel that could cause a nasty idle and hard start. When I first moved to E85 on a previous car it took a few adjustments to get cold starts just right. This wasn't a flex fuel vehicle though, no sensors or anything to help, custom tune was done.

There has to be a sensor in the fuel line that tells the ECM the ratio of gas to ethanol, as it needs to ramp up the injector pulse width the more ethanol in the fuel, so either that sensor isn't telling the ecm the correct info or your fuel pump and filter are not keeping up with the extra flow demand. The sensor PID should be checked with a scan tool and the fuel pressure requires a gauge under load

Or you got a crap batch of fuel.

From the 2017 Expedition Quick Reference Guide:

Use only UNLEADED gasoline blended with a maximum of
15% ethanol and a minimum of an 87 octane rating. Do not use
E85 (ethanol), diesel, fuel-methanol, leaded fuel or any other
fuel because it could damage or impair the emission
control system

Yosemite Sam said:

From the 2017 Expedition Quick Reference Guide:

Use only UNLEADED gasoline blended with a maximum of
15% ethanol and a minimum of an 87 octane rating. Do not use
E85 (ethanol), diesel, fuel-methanol, leaded fuel or any other
fuel because it could damage or impair the emission
control system

Click to expand...

Yes but the OP has a 2010 according to his Profile/Information.
Thats too hard to find for anyone trying to assist.
I always put that info in the post to facilitate assistance or relevancy

I only run E85 during the warm months. Less mpg, but I don't really care. I also run a E85 tune from 5Star for a bit more fun. E85 is harder to start in cold weather. It takes a bit for the pcm to adjust for the ethanol blend, when switching over. So currently I'm running premium with a 93 octane tune, since the weather is colder. I also use the GetUpSide app and get 25c per gallon back on average and blow the cashback on Amazon.

Like Keepinitoldschool noted.

That E85 could have picked up moisture in the station tank. Diesel does that at times when the station tank gets too low and does not have a water separator at the pump.