I can’t for the life figure out this misfire on my 08 with the 4.7 v8 (flex fuel) When I start it up the car misfires but after it gets to operating temperature it runs fine. I started by changing out both spark plugs. Swapped coil packs, replaced the fuel injector and did a compression test. During the spark plug change I noticed it had oil on it. I did remove the valve cover and cranked it to see if the valve lifter moved freely and it did. I should have replaced it when I had the cover off looking back now. I’m not really sure what to do next.

 

Make sure the connector for the injector and coil(s) are clean, tight, and make good contact.