right, just had another look. with the ecu powered up there is 12.5v on all injectors.
and it had 1 bar of fuel pressure

so the ecu switches the ground to the injectors, but what triggers this?

its a phase sensor on a cossie, but this is a zetec lol, it has a cam sensor but this is not plugged in, as there is no plug for it.

but the zetec lobe is different to a cossie, as they use 2 points 90 degrees apart and the zetec only had 1.