issue with ESC calibration and control

Other Hardware Motors, Mechanics, Power and CNC
2

#include <Servo.h>

Servo steer;
Servo accel;

void setup()
{
Serial.begin(9600);
accel.attach(10);
steer.attach(11);
accel.write(180);
delay(1200);
accel.write(0);
delay(1200);
accel.write(90);
delay(1200);

}

void loop()
{
accel.write(84);
delay(1200);

}
This is a basic code for calibration i am using.

Now when i try to write any value below 90 the servo does't work. only with values greater than 90 the servo works.