HI,
I think you need to do a full fuel pressure check including fuel delivery ,
if you have the kit, or some one who knows RS turbo to do it for you,
as you could have a faulty fuel regulator,if you take out one or all of the injectors
and unplug the fuel pump relay (purple under drivers foot well)s2, or silver s1.
and bridge pins 30 and 87 with ignition on the pump will run continuously, and be
careful of danger of spraying fuel, press down the air sensor plate attached to metering unit, and fuel should spray from injectors, but at rest position no fuel should spray from injectors, also with the pump running you should have at the
sensor flap around 2mm of free play before it contacts the metering unit plunger.
be careful not to flood the engine if remaining injectors left in .
if you have fuel, probably fuel pressure.also check the hose from the metering unit to the turbo inlet is secure.

DAVE R