node js multer file upload not working when started with ubuntu upstart

I have a VPS(ubuntu 14.04) and I a nodejs app with multer for handler file upload and it works find when I when I start the server via node ex."node my-server.js"

but not if I start via upstart ex."sudo start node-app" node-app is a ubuntu upstart conf file here is the code

file: /etc/init/node-app.conf

description "node.js server"
author      "Name"

start on (local-filesystems and net-device-up IFACE=wlan0)

stop on shutdown

# Automatically Respawn:
respawn
respawn limit 99 5

script
    export HOME="/home/username/www/jlovesyou-server/"

    exec node $HOME/bin/www 13002 >> /var/log/node.log 2>&1
end script

any idea why is not working via upstart?