In the engine bay I'd check:
+12v Battery power to the relay. <-If missing, possibly bad 25a fuse or bad connection
+12v power to the relay coil. <- If missing, no signal from key switch when starting
Ground at the relay coil.
+12v power leaving the relay. <-If missing, could be bad relay contacts
At the fuel pump I'd check:
+12v power at the fuel pump.
Ground at the fuel pump.
Funnily enough (since you mentioned Bowlsby's wiring harness) I found this:
http://bowlsby.net/914/Classic/zTN_FI_FPChecklist2.pdfIf that all checks out your fuel pump might be bad and getting a bad spot on the brushes.