Problems with SHARP IR and IO sheild

Hi all, I have an Arduino Uno with a dfrobot v5 io expansion shield and I am trying to get decent readings from a GP2Y0A02YK0FGP2Y0A02YK0F Sharp IR Sensor. The sensor connects to the analog ports of the board with a JST connector. This same approach has lead to pretty much perfect readings from a flame sensor connecting to the same pins and being read the same way ( the sensor reads 0 unless a flame is present then the value increases accordingly). When I try the same a method for an IR sensor the readings are pretty consistently about 175, no matter what I put in front of the sensor it does not seem to change the readings. I have already read a lot on the subject but have had no luck. Is it true arduinos have built in resistors on analog pins or is that just a rumor. Does anyone have any advice for sorting out this issue?

I thought posting my code might be useful too. Most of the code pertains to a set of legs for the robot I am building but the rearIR function is for the actual reading.

#include <Servo.h>
#include "Constants.h"
#include "IOpins.h"

//Dual IR pins
//GP2Y0A02YK0FGP2Y0A02YK0F
//20cm - 150cm
//7 inches to 59 inches
int irPin =  A5;
int irReading;
int count = 0;

Servo FRH;
Servo FLH;  // define servos
Servo RLH;
Servo RRH;
Servo FLK;
Servo FRK;
Servo RLK;
Servo RRK;

//Value for knee to make solid contact with the ground
int kneeGround = 140;
void moveForward();
float readIR();

void setup()
{   
  
  pinMode(A0,INPUT);
  pinMode(A1,INPUT);
  pinMode(A2,INPUT);
  pinMode(A3,INPUT);
  pinMode(A4,INPUT);
  pinMode(A5,INPUT);  
  digitalWrite(A0,HIGH);  
  digitalWrite(A1,HIGH);  
  digitalWrite(A2,HIGH);  
  digitalWrite(A3,HIGH);  
  digitalWrite(A4,HIGH);  
  
 delay(5000);// attempted 10 second delay

  // attach servos
  FRH.attach(FRHpin);  // ****TEST**** switched order 
  FLH.attach(FLHpin);  //  of right and left
  RLH.attach(RLHpin);  
  RRH.attach(RRHpin);  
  FLK.attach(FLKpin);  
  FRK.attach(FRKpin);  
  RLK.attach(RLKpin);  
  RRK.attach(RRKpin);   

  /**** Knee orientation is pretty standard, hips are not ****/

  //*Initial Servo Positions*//
  // 2 rear hips
  RRH.write(150);
  RLH.write(30);

  // 2 front hips
  FLH.write(110);
  FRH.write(80);  

  //Front knees
  FLK.write(kneeGround);
  FRK.write(kneeGround);

  //Rear knees
  RLK.write(kneeGround);  
  RRK.write(kneeGround);

  delay(3000);
  Serial.begin(9600);
}

void loop()
{
  //moveForward();                                                             
  //TESTING 
 //Serial.print("Count is ");
  //Serial.println(count++);
  readIR();
} 

//Reads one IR sensor reading
float readIR()
{ 
    
  irReading = analogRead(irPin);
  float volts = ((float)analogRead(irPin))*0.00322265625;// 5 vs = 0.0048828125; ;
  float distance = 65*pow(volts, -1.10);
 
  Serial.print("Real reading : ");
  Serial.println(distance); 
  delay(1000);   

  return irReading;
}


void moveForward()
{   

  ///////////////////

  //Right Front move forward
  //Shift slightly
  FLK.write(60);     
  FRK.write(50);
  FRH.write(30);//move forward
  delay(100);

  FRK.write(kneeGround);
  FRH.write(100);//move forward
  delay(100);
  ///////////////////

  //Left rear move forward
  //Shift slightly
  RRK.write(60);     
  RLK.write(50);
  RLH.write(100);//move forward
  delay(100);

  RLK.write(kneeGround);
  RLH.write(30);//move back
  delay(100);
  ///////////////////

  // Left Front move forward
  //Shift slightly
  FRK.write(60);     
  FLK.write(50);
  FLH.write(150);//135 move forward
  delay(100);

  FLK.write(kneeGround);
  FLH.write(80);//move forward
  delay(100);

  //Right rear move forward
  //Shift slightly
  RLK.write(60);     
  RRK.write(50);
  RRH.write(50);//move forward
  delay(100);

  RRK.write(kneeGround);
  RRH.write(120);//move back
  delay(100);
  ///////////////////
}