Why are my bullets shooting at an unpredictable rate?

var myTransform : Transform; //current transform data of this object

private var startPosition : Vector3; private var chasing = false;

private var rotLock = 0;

var chaseThreshold = 2; // distance within which to start chasing var giveUpThreshold = 5; // distance beyond which AI gives up

var distance; //distance from player var distance2; //distance from start position

private var variableScript; var theBullet : Transform;

public var health = 50;

var attackTimer : float; //a timer that controls frequency of attack var coolDown : float; //the cooldown for each attack

var fov = 60.0; private var hit : RaycastHit;

function Awake() { myTransform = transform; //cache transform data for easy access/preformance coolDown = 2; }

function Start() { target = GameObject.FindWithTag("Player").transform; //target the player startPosition = transform.position; //store the start position }

function Update() { // check distance to target every frame: distance = (target.position - myTransform.position).magnitude; distance2 = (startPosition - myTransform.position).magnitude; ChaseCheck(); CheckDeath(); FixRotation(); }

function ChaseCheck() { if (chasing) { ChasePlayer(); AttackTimer(); }

 else if (LineOfSight(target))
     {
         chasing = true;
     }

 else if(distance > giveUpThreshold && distance2 > 1)
     {
         ReturnToPosition();
     }

}

function ChasePlayer() {

  //rotate to look at the player
     myTransform.rotation = Quaternion.Slerp(myTransform.rotation,
     Quaternion.LookRotation(target.position - myTransform.position), rotationSpeed*Time.deltaTime);

     //move towards the player
     myTransform.position += myTransform.forward * moveSpeed * Time.deltaTime;

     // give up, if too far away from target:
     if (distance > giveUpThreshold) {
         chasing = false;
 }

}

function ReturnToPosition() { //rotate to look at the start position myTransform.rotation = Quaternion.Slerp(myTransform.rotation, Quaternion.LookRotation(startPosition - myTransform.position), rotationSpeed*Time.deltaTime);

         if(myTransform.position != startPosition)
         {
         //move back to start position
             myTransform.position += myTransform.forward * moveSpeed * Time.deltaTime;
         }

}

function AdjustHealth(adj) { health -= adj; }

function CheckDeath() { if (health <= 0) { Destroy(gameObject); } }

function AttackTimer() { //if the attack timer is above 0 if (attackTimer > 0) { attackTimer -= Time.deltaTime; //countdown to 0 } else if (attackTimer < 0) { attackTimer = 0; //error avoidance } //attack when the timer is at 0 else if (attackTimer == 0) { var script : TurretShoot; script = GetComponentInChildren(TurretShoot); script.AutoShoot (); attackTimer = coolDown; //reset timer to cooldown value } }

function LineOfSight (targt : Transform) : boolean { if (Vector3.Angle(targt.position - transform.position, transform.forward) <= fov && Physics.Linecast(transform.position, targt.position, hit) && hit.collider.transform == targt && (distance < chaseThreshold))

         {
             return true;
         }
 return false;

}

function FixRotation() { transform.rotation = Quaternion.Euler(rotLock, transform.rotation.eulerAngles.y, rotLock); }

function Awake() { myTransform = transform; //cache transform data for easy access/preformance

}

function AutoShoot() { var createdBullet : Transform; // create a bullet, and rotate it based on the vector createdBullet = Instantiate(theBullet, myTransform.position, myTransform.rotation); }