Help! 2000 V6 engine misfire

[Long Knife]

My daughter has a 2000 Mustang 3.8L V6 with about 95,500 miles on it and when it starts up it runs really rough. Enough so that the whole car shakes. After it gets up to normal operating temp, it smoothes out and runs great. She was getting the Service Engine Light so I had the code run and it came back saying there was a misfire in the #3 cylinder. I changed out the plugs, wires and even the coil but it still happens whenever it sits long enough to cool down completely. What else can I do to fix it?

Thanks.

 

[wmburns]

First, inspect the electrical connection to the coil pack. Look for bent/pushed pins.

Get a "noid" style testing light. Test the RD/LB wire on the coil pack. The light should flash with each firing. Also test the DB/LG and PK/WH as well. Post the results.

Next, use the noid test light to confirm that the fuel injectors are actually working. Confirm that all cylinder are hitting.