Exceptional work as always. Really may give merit to your theory about limiting recall scope. Now dissect the old one to see how it began to fail……
Didn't think I could tear apart the pump effectively, but you encouraged me to give it a short. Was easier than expected.
Cut apart filter sock - looks good.
Working the head off like a tin can. Can already see that the pump impeller fins have wear.
There's clear wear inside on all surfaces with impeller runout. You can see on the circumference of the housing left of the arrow wear from the impeller. On the impeller itself, aluminum transfer marks on ~1/3 of the wheel showing contact with the housing.
Housing and cap showing wear.
The impeller to motor shaft wasn't even clearance fit and slips right off. I attribute the original failure to wear at this interface, allowing play and slop of the impeller.
In the larger Denso fuel pump recalls, they note -
Low-density impellers inside Denso branded fuel pumps are cracking and limiting the amount of gas reaching the engine. In that failure mode, it would be catastrophic. Albeit more a brittle failure mode. Fundamentally, it still indicates that the impellers may be low-density and weak.
I believe in my case, that weakness manifested in wear at the shaft to impeller interface driving more premature wear. A slow degradation like failure mode wouldn't necessarily be subject to a recall, but 140k miles for a Toyota / Denso design, on a Lexus / Land Cruiser doesn't meet expectations.