Hi,
I have recently had this same problem on my k-jet 16v. To test the injectors you have to bridge the fuel pump relay, connect the battery then lift the flap up in the airbox up then the injectors should spray fuel. If the injectors dont spray it could be your fuel pump not suppling enough fuel(should be 5 bar) but mine turned out to be the metering head, i did try 3 before one worked!!
Tim