serial monitor freezes on arduino uno when data or clock from HX711 is connected to the arduino digital data pin

[NiallMeade]

Whenever I wire my components as shown and run the following code nothing is printed in the serial monitor but as soon as I remove any wires connected to the data pin ( digital pin 4) the arduino will begin printing and eventually starts printing the weight as 0. Even if I connect the clock wire to the data pin the serial monitor will freeze.

`
#include "HX711.h"

static const uint8_t DATA = 4;
static const uint8_t CLK = 3;

HX711 scale(DATA, CLK);

float calibration_factor = -14; // this calibration factor is adjusted according to my load cell
float units;
float ounces;

void setup() {
Serial.begin(9600);
Serial.println("HX711 calibration sketch");
Serial.println("Remove all weight from scale");
Serial.println("After readings begin, place known weight on scale");
Serial.println("Press + or a to increase calibration factor");
Serial.println("Press - or z to decrease calibration factor");

scale.set_scale();
scale.tare(); //Reset the scale to 0

long zero_factor = scale.read_average(); //Get a baseline reading
Serial.print("Zero factor: "); //This can be used to remove the need to tare the scale. Useful in permanent scale projects.
Serial.println(zero_factor);
}

void loop() {

scale.set_scale(calibration_factor); //Adjust to this calibration factor

Serial.print("Reading: ");
units = scale.get_units(), 10;
if (units < 0)
{
units = 0.00;
}
ounces = units * 0.035274;
Serial.print(units);
Serial.print(" grams");
Serial.print(" calibration_factor: ");
Serial.print(calibration_factor);
Serial.println();

if(Serial.available())
{
char temp = Serial.read();
if(temp == '+' || temp == 'a')
calibration_factor += 1;
else if(temp == '-' || temp == 'z')
calibration_factor -= 1;
}
}`