I right-click package.json file in my project and choose "Debug as"-> "NPM ..." in the menu. Then type "start" to the "Goal" text box.
After that, I can see this error message in the Console:
"execvp(): No such file or directory"
However it writes nothing else about the problem. When I run "npm start" from command line, it works fine.

If it matters, my system is Mac OS X 10.9