At this point, I'm running out of ideas that aren't expensive... Going more on theory than anything else. Possibly a crack or some defect in that particular element that opens up and lets high pressure fuel leak back when the pump heats up?

Oh, and just a reminder, make sure you put that #4 adjustment tab back exactly where it was originally.

__________________
-Evan


Benz Fleet:
1968 UNIMOG 404.114
1998 E300
2008 E63


Non-Benz Fleet:
1992 Aerostar
1993 MR2
2000 F250