Fuel door does not reliably open

[johnpagenola]

I have a 2011 Lincoln Towncar and its fuel door does not reliably open when I press the button on the bottom of the driver door. The Lincoln dealer gave me the part number 8W1Z-54405A26-A to get a new fuel door assembly. I ordered and received this part. Unfortunately, the fuel door assembly did not have the associated spring that pops the fuel door open. Is the spring another part number? If not, where can I get a new spring?

Thank you.