[sierra]

Originally Posted by RossGA

We must remember that the fuel that is being pumped is also the lube for the pump itself. Ethanol has much different lube characteristics than fossil fuel based gasoline, and that might explain the issue.

Typically, in order to run ethanol, certain design precautions have to be used in the fuel system so the system can handle these differences. It would seem, that the initial fuel pumps on these motors did not meet this criteria. If the new pump has a new part number, they most likely made some adjustments to properly handle fuels containing ethanol.

I was specifically warned on another car that the pump and injectors were not designed to handle ethanol. The USA has notoriously crappy gas too (we get the cheap quantity, but not the high quality), and it is possible that in other places in the world this is not a problem, and wasn't realized by Subaru/Toyota until the cars came to North America.

That about sums it up.
Mind you it's all been said many times before but it might help a few who can't be bothered to read through the threads to understand the problem.