[Ducati] 748SPS Fuel Pump Question

[Kerry and Brad Black]

the only ways a fuel pump can run continuously with the ignition on, but engine not running is if the relay has stuck on, it's previously been hardwired, the ecu has a fault, someone has modified the ecu/eprom software specifically for the pump or there's some sort of short within the wiring loom.

the relay power in is fed 12v whenever the key is on.  the switching is done by the ecu.  it turns the pump on for a predetirmined time when the key is first turned on, then again when it receives a rotation sensor signal.  for as long as it recieves a rotation sensor signal it will keep running the pump.  which is a good way to diagnose a rotation sensor issue - if the pump doesn't run when you crank it, there's an issue of sorts there.

it has nothing to do with pressure, as there's no pressure sensor.

brad