You said you put in new glow plugs and that they are working ----- you did say that, correct. I'll assume that there isn't any need to ask how you know. Beyond that, a diesel needs fuel, compression and air. Check all three --- clean fuel filter? Clean fuel?? When you replaced the injectors, did you bleed the fuel system through the injectors?? Clean air filter??? What's the compression ---- should be around 450 psi or so?? If all three are good and nobody messed with the engine timing, it will run.