I changed out a Blown 5.4 3v in my 2004 F150 with a 5.4 3v from a 2008 Expedition, Vin5 . Wont idle, cuts out, runs bad unless in limp mode with cam sensor unplugged- P0340 code- wiring, sensor and PCM Check good. Are there Cam or such mechanical changes that could cause this?
Thanks Ahead!

 

Mechanically,those 2 engines are identical. You've got a problem with wiring,etc.
JL

 

Thanks for the response.
I checked the wiring, ohmed out the pinouts and the sensors, even yanked the intake back off to be sure no pinches etc. bought a new pcm, no change- took to ford and they couldnt figure it out after 3 hours, reprogramming the pcm and even changing the connectors on the cam sensors.

I dont know where to go from here. Suggestions? Points and condensors on my 66 bird is much easier.

Thanks

 

My suggestions-swap EVERYTHING electrical from the old engine onto the new one. I don't have all the specifics in front of me,but there's something there that the PCM does NOT like. I'll assume that you put new plugs in it?
JL
edit-one other thing-you didn't possibly swap o2 sensor connections and have bank1 plugged into bank 2's harness, and bank 2 plugged into bank 1's harness did you? MAF good and clean?

 

I used the plugs in the 08 as it has 46k on it, the only electrical i didnt move were the knock sensors on the block under the intake- i will look at the o2 sensors- i didnt think the wires could reach the others, but something is not quite right. MAF is clean- even cleaned it more to be sure.
i will yank off the intake again and change out those sensors and let you know.
Thanks

 

just finished changing the last sensor and no change. the o2 sensors wouldnt reach across. Possible timing jump 1 tooth?

 

Tore apart the front of the engine saturday, chain was off 2 teeth on bank 1. redid both chains, now runs Great! no more codes.
Thanks for all the help here.

 

That's where I would have went with it if I would have been troubleshooting it after I checked all of that other stuff.
JL