[Ducati] 748SPS Fuel Pump Question

[Larry Kelly]

On Feb 9, 2007, at 3:01 AM, Veloce916 at aol.com wrote:

> Are there any models that the fuel pump continually runs on when  
> the engine is not running "sounds almost like it is circulating  
> back to the tank" or should they all reach pressure and shut down  
> until the pressure drops again.


If the ECU fails to detect a running engine during the initial pump  
run at startup, the pump is switched off. This is a safety feature,  
not a function of pressurizing the system initially. If you crash and  
rupture the tank or fuel lines, fuel would continue to flow, with the  
key still on, over a hot engine - potentially a fire hazard.

After the engine starts it runs continuously. So there’s nothing to  
turn it off until you stop the engine. It doesn’t just shut itself  
off when it reaches it’s operating pressure or keep running if it  
doesn’t..

I’m not sure what signals the ECU that the engine is running. It  
could be oil pressure or the RPM pick-up sensor. So it seems that if  
the pump stays on during initial startup there’s a sensor circuit  
problem or an ECU issue.

Larry Kelly
'95 916