ESC is not working properly

I’m noob to bldc motors and ESC , sometimes ago I bought 4 brush less motors(1400kv) and 4 ESC (30Amp) now problem is that each ESC starts at different PWM signal some works between 1100 to 1500 microsecond pulse and some between 1800 to 2500 microseconds .
So are my ESCs are not working or is there any way to fix this ?

If you give some details of the motors, the ESCs and how you are powering them we'd have a better chance of helping. Most normal motors/ESCs, once they have been successfully armed, start trying to run at around 1100 microseconds and are at full speed by about 1900. Most BLDC problems are caused by insufficient power or the wrong arming sequence.