Unable to use ir receiver and motor shield together

#include <IRremote.h>
#include <AFMotor.h>
AF_DCMotor motor(1);


int RECV_PIN = 14;//The definition of the infrared receiver pin 11
IRrecv irrecv(RECV_PIN);
decode_results results;

void setup()
{
  Serial.begin(9600); //Open serial 
  irrecv.enableIRIn(); // Initialization infrared receiver
  motor.setSpeed(255);
  motor.run(RELEASE);
  Serial.println("start");
  motor.run(FORWARD);
  delay(1000);
} 

void loop() 
{
  if (irrecv.decode(&results)) {
    if(results.value==0x3D9AE3F7)
    {

      motor.run(FORWARD);
      delay(2000);    
    }
    else if(results.value==0x1BC0157B)
    {
      motor.run(RELEASE);
      motor.run(BACKWARD);    
    }
    Serial.println(results.value, HEX);//Wrap output in hex receive code
    Serial.println();//For ease of viewing the output to add a blank line
    irrecv.resume(); //Receiving the next value
  }
}

Motor shield is not working when I use an IR receiver.
I tried connecting the ir receiver in different analog pins but it didn’t work. I guess it’s due to some error in my code but unable to figure out.