I can graph the fuel rail pressure using the torque app on my phone. What your seeing is three attempts at starting the car. Pressure begins at just under 2000, slowly builds and finally starts on the third attempt when it gets up to around 3000. I don't have the test IMV unit like you say so I cant test pump functionality on its own. The cheapest way would be to swap out pressure sensor but still seems like a stab in the dark. I have ordered one anyway for about £65 off ebay. Not too shabby if it does fix the issue.