if (i == 3)
{
  for (int m = 0; m <= i; m++) Instantiate (Obj1, new Vector3 (1f, 1f, 1f), Quaternion.identity);
    i=0;
}

using UnityEngine;
using System.Collections;

public class particleEnablee : MonoBehaviour {
    ParticleSystem compoPa;
    int timeManaGer;
    void Start () {
  compoPa = GetComponent<ParticleSystem> ();
  timeManaGer =0;
    }
    
    // Update is called once per frame
    void Update () {
  timeManaGer++;

  if (timeManaGer > 100 & timeManaGer < 200)
  {
   compoPa.enableEmission = true;
  }
   else compoPa.enableEmission = false;
    }
}