Might be worth a check of the clear (probably brown now) line on the backside of the IP back up to the filter housing. If the banjo bolt is loose or the line is cracked, it's possible for fuel to leak out under gravity through the return line.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]