My memory with this is hazy,I've not had an RST since 1998 and been to sleep since then. Really need a wiring diagram or an old proper Ford workshop VSTM (vehicle system test manual) to check out this fault.

Info must be online how they operate exactly,somewhere.

Has the car got an aftermarket alarm/immobiliser on?

Wonder if where they've spliced into fuel pump circuit the connection is poor or whatever?