hey so lastnight I start my truck 2001 ford 150 with 5.4 and it was running rough until it warmed up and started to run fine. this morning it through a code a me p0306 was running rough again until she warmed up again. so what do guys think it is I'm going pull that plug tomorrow and see what it looks like. I just find it weird on how it runs good when its warm ps if was a thread on this sorry couldn't find it thanks

 

Check the plug and the fuel injector. You probably have a leaky/dripping fuel injector, which will cause a wet condition when cold, and give you a misfire until it warms up and burns off the residual fuel.

 

now I'm really confused. so I let it cool down all the way let it sit for about 5 hours. started it and it ran like top doesn't make sense to me.

 

Pull the plug. If it's wet, then the injector is leaking or the plug or COP isn't firing right.

To your question. In 5 hours, probably day, the engine is still warm from the drive and fuel will vaporize until the temps come down to ambient air. Once it gets really cool, or overnight (cool temps/dew point, etc) the fuel doesn't evaporate like the heat of the day. The misfire can start until it burns off the wetness. It could very well be a COP or the plug. Your description sounds like the injector dripping. Pull the plug and see if it's wet in the morning after sitting overnight. If it's wet, then the injector is leaking most likely. You can run a good injector cleaner and see if that cures the problem if that ends up being your findings.