I inspected the injector pump delivery valves. All valves looked good with the exception of the two nearest the front bumper. Valve holders' outsides were badly corrosion. (see photos). Fuel (or water?) appeared to be dirty and clear for the corroded valve bodies. It was very smooth and clean on the valve faces, so I reassembled it with new copper washers for now, cleaned it and reassembled it. The beginning was rough, then smooth, then I thought "I have it", then it became worse. Sure enough, there was the same level of air infiltration.

Why is the corrosion occurring? If the valve body faces are still smooth and the valve holder nor delivery valve interface have been corroded, do those factors still cause concern?

For now, I have ruled out the delivery valves. I'm expecting a rebuild kit for the lift pump this weekend. Can you think of any other sources of air infiltration?

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Theseus

Instragram: doss_project
1984 300SD - 930 Blue, OM 617
Murfreesboro, TN

Theseus owned a ship in Greek mythology, and when a part of the ship needed replacing, it was replaced. Eventually, everything was replaced. Is it the same ship? (I own the car of Theseus. )