display 16x2 i2c + sensor de fluxo

Hello everyone, everything good? I’m having a big problem here, I want to display the leak in liters on a 16x2 display with i2c communication but I can not get it up to now, I tried several things and nothing! any message I add before displays normal but to display what I want it to be “vazaoagua” does not display and when I leave to display along with the serial, does not even show on the serial, if anyone can help me series very grateful.
follow the code below:

int Pulso; //Variável para a quantidade de pulsos
int j=0; //Variável para contagem
float vazaoagua; //Variável para armazenar o valor em L/min
float valormedia=0; //Variável para tirar a média a cada 1 minuto

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x3f,16,2);

void setup()
{
Serial.begin(9600);
pinMode(2, INPUT);
attachInterrupt(0, incrpulso, RISING); //Configura a porta digital 2, para interrupção
}

void loop ()
{
Pulso = 0; //Começa do 0 variável para contar os giros das pás internas,ek segundos
sei(); //liga interrupção
delay (2000); //Espera 2 segundos
cli(); //Desliga interrupção

vazaoagua = Pulso / 5.5; //Converte para Litros/minuto
valormedia=valormedia+vazaoagua; //Soma a vazão para o calculo da valormedia
j++;
//lcd.begin();
//lcd.setCursor (1,0);
//lcd.print (vazaoagua);
Serial.print(vazaoagua); //Imprime na serial o valor da vazão
Serial.print(" L/minuto - “); //Imprime L/min
if(j==60)
{
valormedia = valormedia/60; //Tira a valormedia dividindo por 60
Serial.print(”\n Media por minuto = “); //Imprime a frase valormedia por minuto =
Serial.print(valormedia); //Imprime o valor da valormedia
Serial.println(” Litros/minutos - "); //Imprime L/min
valormedia = 0; //Torna variável valormedia = 0, para uma nova contagem
j=0; //Torna a variável 0,para uma nova contagem
}

}

void incrpulso ()
{
Pulso++;
}

First use an I2C scanner to verify the address, i.e. the value 0x3f in
LiquidCrystal_I2C lcd(0x3f,16,2);The scanner is a sketch that you upload and run, with you display connected as already done. It should detect the display and give you the correct value of the address. Change it if it's not 0x3f. If this is correct, then...

Second, try to run the examples of the library, to see if the display works.