Ok so I have an 04 f150 with the 5.4 in it. It had been having running issues and its only gotten worse since working on it.
So what its doing:
barely idles at all. Seems like its missing on multiple cylinders but never throws a code. Idle is 500 rpm or under. It barely has enough power to get the truck moving......surges andmisses. Only two codes its throwing are bank 1 and 2 lean.

now what ive done:
Replaced all of the plugs with oem motorcraft. Replaced all of the coil boots. Fuel filter. And one bad coil. Replaced one bad upstream 02 sensor.The cats were totally plugged off so thats fixed as well. Fuel pressure koeo settled at about 50ish koer was 34. Reved the engine up to 3500rpm and fuel pressure never dropped lower than 34. Hung around 36 to 40 psi.

So whats the next step? Im about to drive this truck off a cliff.

 

Oh, also forgot I threw a light on each of the coil wires and injector wires. All were getting pulses.

 

having the same issue with mine, turns out there is a vaccum line on the back of the intake man that has blown off, a real PITA to get too, waiting of her to cool off and about to tackle the job, have to remove air system and fuel rail to maybe get back to it, mechanic told me at the dealership this is a common problem on these trucks and it fools a lot of people, try and get the line hooked back up with a zip tie on the collar. I will let you know later if this is the fix!

 

Yea let me know what ends up hapening. The only thing that makes me think that isnt the issue is that the brakes dont feel hard like im loosing vacuum to the booster. I assume this is the line your talking about?

 

found the vacuum line and it was off! got it back on and it runs perfect now! It was a very difficult task though, almost impossible to see and get to

 

Glad u got it fixed. I was going to suggest unplugging the MAF to see if it ran better.

 

its weird I had similar thought but I guess because of sensors my truck will barely run at all it the air filter is not in it and wont run at all if the MAF sensor is pulled. never seen a vehicle that would almost stall out just by pulling the air filter out

 

I ordered up a new one just in case. I had already tried cleaning it but there was no change. Will let you guys know if it fixes it when it arrives.

 

Tried the new MAF sensor. No change in running condition. ...

 

Any other ideas?

 

U might have water in the fuel. Put some Heet in. Not likely to fix bit its a cheap thing yoi can do.

 

Yea, I already ran the tank almost dry and filled it up. Didnt make any difference unfortunately.

 

Did you have your catalytic converters checked to see if they are maybe stopped up?

 

Yeah, I have an 04 fx 150 if you can sell or trade it in... I have 144K miles and the problems only grow! Get rid of it if you can, I'm unfortunately stuck with it and guess what? I'll never buy any ford again.

 

absolutely no help at all! thanks for that...