firstly check fuel getting to metering head at correct pressure-then moving plate check it comes out of all the fuel outlets
you need to bridge the fuel relay or put a constant live to get the pump running when you want rather than when engine is running
have seen these with all 4 injectors crudded up-same as vw golf gti[although they are worse as tank filler neck rots/falls into it] check flow into bottles[safely now...]
metering head needs to be spotless as does all the rest-plate has to be in correct place in cone
fuel pressure has to be right too