I’m here to share with you something happen with my XKR SC 2002 with 62 000 km.
my engin start but stall immediately, No Check engin light but some codes with SLM (security looking module) I don’t think it have relation with my engin issue, so I changed the 2 fuel pumps and filter nothing happens, after few sec key On the pressure fuel drop to 0, but something happens when I checked my pump relay (the car have 2 relays one on trunk fuse box and the second I can’t find it!) when I remove the fuel pump relay R4 the car start and run.
It sounds like you have found the standard test for the secondary pump in the 4.0L XKR
If the car will run with Fuel Pump Relay 1 out, unfortunately, it means that there is still a problem with the primary, so you need to re-check what you have done (pump, connections, wiring). The Fuel Pump 2 relay location is shown here in this clip from the 2002 Electrical Guide:
Note that the car will throw a P1230 fault if you run with the primary relay #4 removed.
