I am posting for a co worker, he has a 09 F150 when he first starts it up it idles and runs like crap, if he drives off without letting it run for awhile the truck will literaly fall on its face, but after it warms up it runs great. Any ideas? I thought maybe crack in the intake or somewhere that when warmed up would seal.

 

I wouldn't think injectors would be clogged already, but who knows. Have him take it to the dealer, its still under warranty.

 

Exactly, that's one of the joys of owning a new truck!

 

It sounds like a bad coolant temp sensor. The PCM is being told then engine is warm even when it isn't.

Time to use that warranty.