Help no fuel from injectors

Had metering head apart cleaned painted etc put onto car and started fine stopped engine after running a while due to small water leak tried to start again later now will not fire up.
removed an injector no fuel coming out while turning engine over, if I power up fuel pump and lift air meter disc fuel comes out of injector but not if I turn it over.
looks like either the disc is too hard for the manifold vacuum to lift or vacuum pressure is too low.
please help with any ideas

Metering heads hardly ever go wrong but you have messed with it so go back and check for blockages and the air plate moves up and down freely

You say there is no fuel while cranking it over? Try this but be careful and don't let your engine run for long with this….

Put your horn relay no.53 in your fuel pump relay position. This will run the pump from the ignition on.

Just to rule out faulty relay.

If all is good try checking the pressure of the fuel especially after the WUR regulator as these are buggers for going wrong.

If still all good try checking the acumilator by removing the tiny screw at the end of the unit, if fuel comes out its buggered.

Good luck mate