Cannot set Pins to LOW I am controlling 2 motors from my Arduino Pro Mini and L293D motor driver module. Problem is, I have to set a pin high and after 1 second set it to LOW. But that doesn't happen... The pin just stays HIGH and is never LOW. 

Here's my Code - 

    int IN2Left = 10;
    int E1 = 12;
    int E2 = 7;
    int IN3RevRight = 6;
    int trigPin1 = A0;
    int echoPin1 = A1;
    int distance1 = 0;
    int IN4Right = 5;
    int IN1RevLeft = 11;

    void setup()
    {
      pinMode(IN2Left, OUTPUT);
      pinMode(E1, OUTPUT);
      pinMode(E2, OUTPUT);
      pinMode(IN3RevRight, OUTPUT);
      pinMode(IN4Right, OUTPUT);
      pinMode(IN1RevLeft, OUTPUT);
      pinMode(trigPin1, OUTPUT);
      pinMode(echoPin1, INPUT);
      pinMode(13, OUTPUT);
      Serial.begin(9600);
    }

    void loop() {
  digitalWrite(13, HIGH);
  digitalWrite(E1, HIGH);
  digitalWrite(E2, HIGH);
  digitalWrite(IN2Left, HIGH);
  digitalWrite(IN4Right, HIGH);
  delay(3000);
  digitalWrite(IN4Right, LOW);
  digitalWrite(IN3RevRight,HIGH);
  delay(500);
  digitalWrite(IN3RevRight, LOW);
  digitalWrite(IN4Right, HIGH);
  delay(1500);
  digitalWrite(IN2Left, LOW);
  digitalWrite(IN1RevLeft, HIGH);
  delay(500);
  digitalWrite(IN1RevLeft, LOW);
  digitalWrite(IN2Left, HIGH);
  delay(100000);
    }


The IN2Left Pin never goes LOW... I am assuming a faulty Arduino but my Arduino seems to be working just fine as it runs other stuff (tested blink and reading an Ultrasonic sensor) just fine.

My deadline is 2 hours from now...

EDIT: Here's the complete void loop function... Note the two pins on top which go HIGH? They Never go LOW again in the entire code.
Your code sets it high, delays for 1000ms, sets it low, and then... turns around and sets it high almost immediately after. Try delaying in between.