This guy always does really good "real world" videos. I came across one he did to test ethanol-based fuels with and without stabilizers. Luckily, modern cars can tolerate the ethanol better than a lawn mower carburetor. At about the 8:00 mark you can see some really nasty, white corrosion. That's the same stuff I found on my fuel pump and hanger when I pulled it last, though mine wasn't NEARLY as bad. I had what I'd call "freckling". It concerned me, but not enough to worry - yet. I haven't rechecked it, mostly because I wanted to keep everything sealed up. I will pull the pump and hanger once I fill up on some pump gas. I don't want to introduce any more air into the ethanol than I have to.
Anyway, I thought it was an interesting read, though it may not correlate directly to our cars, since our fuel systems are up to date. Still, it gives me that much more motivation to run the occasional tank of pump gas

 

My car sat for a year with a 3/4 tank of E90 while the motor was down. No issues. I had the injectors cleaned and they didn't even need it.

 

You also live in a very arid climate. When my Evo 10 was down for a year the first time, with the motor out and the fuel line open to the atmosphere my fuel pump looked like below and it was leaning out.

This was in California, so pretty arid but not like Nevada. Also sea level and right next to the bay.

My car was down seven months this time and I am going to pull the pump again to upgrade. I'll take photos of what it looks this time.

My Evo 8 was not driven for more than half a year, but nothing was open and everything looked peachy fine, like your experience.

 

Leaving the fuel system open is never a good idea.

 

Mine wasn't even left open very long I only removed the fuel pump long enough to push in the relief valve. The next time I opened it up, it had the speckles of corrosion. If I remember right, the car was left with Low fuel level in the tank.
I'm not sure if any of that has to do with my results, but maybe the bit of air that got in Was enough to cause the small spots. Also, my fuel level sensor is a lot slower to react now And occasionally reads a lower fuel level than what's in the tank.

Not the end of the world, everything else still works perfectly.

 

my car is down waiting for a turbo, ill pull my 255 and see what it looks like. 9+ years of E85 only. Pics to come

 

That oxidized fuel pump looks exactly like galvanic corrosion. You made an anode-cathode system and made the fuel pump a cathode.

Can we please stop making threads on the use of E85, it's 2019 and E85 use is a well proven out thing. If you're having issues with your fuel system the issue isn't ethanol.

 

well technically Radium made it

but yes, leaving the fuel line open is what made the magic happen.

I’m not *****ing, I know exactly what happened and I know Ethanol well, I even posted my own “long term use of ethanol” thread on this forum like 10 years ago.

I agree with you

 

I thought it was fun and interesting and related to a few, semi-recent posts regarding corrosion on pumps. My bad.

 

I had the same thought when I saw that image in his thread.

Is it the o2 or other molecules from the air creating the electrolysis like corrosion? Or a ground/electrical issue related to the fuel pump? What would cause this?

 

Fuel system sat, closed, for a few years with E85 in it. I am now in the market for an anodized fuel rail.

 

Interesting seeing this. Think I'm going to convince myself to run 93 after a few E85 fill ups to try and keep stuff happy.

 

All bets are off with the car sitting for a couple years with the fuel system stagnant.

I def wouldn’t keep e85 in the system sitting for that long but I know it’s not always an option to flush it out before it will be standing that long.

 

That's literally just some minor corrosion. That could've happened with gasoline lol

 

E85 is hygroscopic, if you let it sit it will pull moisture out of the air and corrode stuff.