I have a '06 F-150 xlt with the 5.4L auto. It has been acting like it is misfiring when i accelerate hard or go to pass. I know there is alot of talk about the coils or the MAF. I cleaned the MAF already. I recently put a new fuel pump in it and fuel filter. Changed the air filter also. During the pump exchange the fuel line connectors broke and of course you gotta get them from the dealer. I bought the whole line assembly but yet have had time to put them on. What i did was i used regular fuel line and i know that you aint suppose to but i needed the truck to go to work. LOL. I noticed the problem before i changed the pumps but i dint know if it was sucking air from the rubber lines if it would cause it to run like ?? The old pump had one of the fuel line nipples cracked so it was spraying gas and i thought this would cause it to run like was. Any help would be greatly appreciated.

 

before you repace everything take a fuel pressure gadge and check the fuel pressure. If you need the spects on what the fuel pressure should be go to alldata.com

 

you should probably replace the fuel line if they are leaking fuel. but that’s just my opinion. Hypothetically speaking you could leave the line the way they are and continue to spew extremely flamable fuel everywhere, just saying.

once you fix the fuel lines then move to the next step. see how its running.

 

To above poster, very well put. I guess its easier to replace a truck after it burns down than it is to fix correctly.

 

I have an 05 with the same problem (72,000). I changed the fuel filter didn't stop the problem. I had multi misfire code so the ford dealer told me to change my spark plugs. (I changed the sparks plug without breaking any of them.) The plugs were the problem.

 

I did replace the lines with the original lines from factory and still have the problem. It was not spewing gas everywhere. It was before i changed the old pump but as soon as i noticed it leaking gas i changed the pump.

 

a buddy and i had the exact same problem, i wrote two long paragraphs on this in the last two days on other threads, if you can find them great otherwise heres the quick version. The boots that run between the coil pack and the plug was the exact problem for both of us, he replaced his (and it came with new inner springs) i check for cracks, cleaned them, and re dialected grease them. Both of us have had no problems since! Good luck