Fuel flow measurement

[Will14]

Evening all

I want to check the flow rate of fuel being delivered from the tank to the fuel rail, I have read the manual and the procedure seems simple enough

I have just one query, can I just removed the fuel delivery hose put the end into a measuring jug and switch the pump/kill switch on for 30 seconds to take the measurement or do I need to do as the manual says & disconnect wires from the ECM to power the pump? Not sure that I'm keen on doing that as past experiences have taught me those pins can break easily 

Thanks in advance

Pete