Hi!
You should check first that actual injentors are small for the output power. You should be able to measure duty cycle of them. (80%-85% maximum).
One thing you could do is raise fuel pressure, it´s an easy thing to do.
If none of these thing gives you enough fuel, then I´d go for bigger injectors.
Originals are 348cc/min (I think, somebody correct me). Some guys in here are using Siemens Deka 650cc/min, but the have bigger modifications, not just a turbo upgrade.

Hope this helps.