hi i had an injector go but only one, this cost me nearly £400 to renew the one, but this came up as a fault and the car went into limp mode. so it was deffinatly the injector. mine has black smoke when it goes onto turbo as they all do. this does not solve your problem, but injectors are very exspensive, sounds more like the pump or some thing along those lines. can you not have a diagnostic done.