Truck is a 2005 f150 5.4l.Truck runs fine when cold.But as soon as it warms up it has NO acceleration.I mean real bad.Has new Jasper Engine and ne rebuilt transmission.So far I have replaced Fuel Pump and filter,Coils,plugs,throttle position sensor,vct solenoids,crankshaft position sensor,Drivers side camshaft position sensor,mass airflow sensor,02 sensors, cat converters,cleaned air filter,new alternator,new starter,new battery,purge part by brake booster and I'm sure a few other things I cant rememeber right now.Im buying the other passenger side camshaft sensor today to out on.But I'm to the point of no return on this truck.Would appreciate any advice.Also checked for vacum leaks and dont appear to be anything obvious.What parts start to kick in or work once engine warms to a certain temp????Would like to limit the next new parts to this problem first.Thanks

 

If it's running that bad, there has to be a pending OBD code. You should scan it to see what's going on.

 

It's not throwing a code.Ive driven it for months at a time.In really hot humid weather it runs even worse.Forgot to mention I replaced all 8 fuel injectors with motorcraft injectors and it dosnt make any difference either.

 

Ok just scanned and I'm getting p0174 Lean on bank 2.No check engine light lit.But scanner I bought is showing this code.I did another test for vacum leaks with carb spray and propane.Cannot find a thing that's sucking air.Truck is driving me crazy...

 

See. I told ya...pending code.

Look carefully at the lines, including those in the very back of the engine...

Kind of like this: