Fuel rail deposits.. what causes them?

I found a white to yellow, chalky substance adhered to the inside of the fuel rail on my '97 Elantra. This led to the failure of the fuel injectors. I was wondering if anyone has seen this before and what causes it. Bad gas? Water in the gas? Ethanol? Aluminum oxide formation from the aluminum fuel rail itself?

Here is a pic of what I’m talking about.

The most likely thing is basically cheap gasoline - not so much for what it has in it, but for what it doesn’t have in it (adequate detergents).

Have a gander at these links:

I’d clean it all up and start going with Top Tier providers.

Water almost surely plays a role in this, and ethanol can harbor water.

“…ethanol attracts water.”

I wouldn’t put it quite that way. Ethanol absorbs water, but it doesn’t attract it. Attraction is a force that pulls on something; like magnetism. That’s not the process here. If water happens to come in contact with ethanol, there is an excellent chance one will absorb the other.

Thanks, all. The first article was interesting in that I didn’t know about the scaling back on detergent formulations and mixing of grades, etc. I wound up replacing the entire rail and injector set with used ones from a junker. I get gas at a variety of stations, so I can’t single out any one place.

Aluminum is NOT the best metal for this application…14 years is a long time…Did dissimilar metals meet at that connection? The injectors all have voltage applied to them.

I’m in agreement with Caddyman about the use of aluminum on something like this. Most are steel.

Moisture and aluminum has also grounded airplanes, led to costly repairs, and on occasion has even dropped one to the ground vertically; sometimes in pieces.