INT1 ERROR.

Dear friends,
Can anyone help me with this?
I am using an Arduino UNO. I am using interrupts. My program is working well when I use INT0, but I just change the pin number and the results are quite different, thousands of pulses are received, contrary when I use pint 2(INT0). Is there any difference in HW inside the chip?.
This is my program.

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#include <LiquidCrystal_I2C.h>
#include <Wire.h>

const int InterruptPin = 3; // Interrupcion One(0) pin 3 Arduino UNO
int contador=0; //Contador de pulsos
int Anterior = contador; //Antes int
byte Monedas=0; // Numero de Billetes depositados
double Precio=0; //Total Dinero ingresado con 2 decimales
int Duracion=0; // Duracion del pulso negativo

LiquidCrystal_I2C lcd(0x3f,20,4); // Direccion 0x3f obtenido por scaner

void setup(){
//RUTINAA CONFIGURACION DEL DISPLAY//
lcd.init();
lcd.begin(20,4); // initialize the lcd.
lcd.setBacklight(HIGH);
lcd.setBacklight(HIGH);
lcd.home();
delay(250);
lcd.print("AGUAS AMAZONAS CORP.");
delay(500);
delay(500);
lcd.setCursor(0,1);
delay(1000);
lcd.print("WATER VENDING");
delay(1000);
lcd.setCursor(0,2);
delay(1000);
lcd.print("Copy Right...");
delay(1000);

delay(1000);
lcd.setCursor(0,3);
delay(1000);
lcd.print("AGUA FRESCA SIEMPRE.");
delay(100);

//RUTINE INTERRUPT 1

digitalWrite(InterruptPin, HIGH); //NEW FOR NOISE SUPRESSION ENABLE PULL UP
pinMode(InterruptPin, INPUT);
attachInterrupt(digitalPinToInterrupt(InterruptPin), CoinAcceptor, FALLING);
// Por flaco de bajada
interrupts(); //adicionada por OmarE
}
void loop(){
Duracion=pulseIn(InterruptPin,LOW); // Mide duracion del pulso en microsegundos
if(Anterior!=contador){
Display1(); // Muestra mensajes
Anterior=contador; // Almacena el ultimo pulso
}

if (Anterior=contador){

switch (contador){
case 1:
//Precio+=1000; //Billete de 1000
Monedas++;
Display();
contador=0;
break;
case 2:
//Precio+=2000; //Billete de 2mil
Monedas++;
Display();
contador=0;
break;
case 5:
//Precio+=5000; //Billete de 5mil pesos nueva
Monedas++;
Display();
contador=0;
break;
case 10:
//Precio+=10000; //Billete de 10mil
Monedas++;
Display();
contador=0;
break;
case 20:
//Precio+=20000; //Billete de 20mil
Monedas++;
Display();
contador=0;
break;

default:
Monedas++;
Display();
contador=0;
break;
}

}

}

void CoinAcceptor(){
contador++;
Precio+=1000;
}

void Display(){
lcd.setCursor(0,2);
lcd.print("MONEDAS: ");
lcd.setCursor(8,2); //Posicion # Monedas
lcd.print(Monedas); // AL DECLARARLO BYTE NO HUBO NECESIDAD
lcd.setCursor(12,2); //Posicion Duracion pulso.
lcd.print(Duracion); //Escribe Duracion pulso
lcd.setCursor(0,3); //Posicion PRECIO
lcd.print("VALOR:$ ");
lcd.setCursor(7,3); //Posicion PRECIO
lcd.print(Precio); // AL DECLARARLO BYTE NO HUBO NECESIDAD
lcd.setCursor(18,3); //Posicion Pulso
lcd.print(contador); // AL DECLARARLO BYTE NO HUBO NECESIDAD
}

void Display1(){
lcd.setCursor(0,0);
lcd.print("GRACIAS POR ELEGIR..");
lcd.setCursor(0,1); //Posicion # Monedas
lcd.print("PROCESANDO..."); // AL DECLARARLO BYTE NO HUBO NECESIDA
delay(500);
//lcd.clear();
}

Pullup might not be working... These look like they are in the wrong order.

digitalWrite(InterruptPin, HIGH); //NEW FOR NOISE SUPRESSION ENABLE PULL UP
pinMode(InterruptPin, INPUT);

To set pullup, first set pinMode to INPUT, then write HIGH to the pin.

Or use PinMode(InterruptPin, INPUT_PULLUP);

You are using the same pin for an external interrupt and pulseIn() which is unusual, and I’m not sure these two uses are compatible.
Also, the variables which are set in the interrupt service routine, contador and Precio must be declared as volatile to prevent the compiler using copies of these variables which may get out of date.

Did you move the wire from Pin 2 to Pin 3 when you changed the interrupt pin from 2 to 3?

I did everything suggested and nothing happened.
First moved the position of instructions pinMode and digitalWrite, then I declared volatile variables and finally I assured the wire was connected to pin3 of the Arduino instead of pin2.
It is strange with pin2 (INT0) the program works good, but no with pin 3(INT1).
2 pulses are recognized as 14 pulses.