So last week I went to start up my expedition and when it started it acted like i lost complete power and started to die (like battery disconnected when running) but all power came back before engine died out. That repeated 4 times in a matter of 10 seconds. After the 4th time engine ran good no issues. So i drove home, made a stop at the Gas station to get a drink. Turn truck off and restarted just fine. After 5 min of driving after the the Gas station stop, I felt a Slight misfire( engine light came on just before misfire started) I got home and parked it and went to bed I was gonna look at it in the morning when I woke up. So next morning, I start it up and No misfire at all, completly gone. I take it for a test drive and it starts slightly misfiring again after about 7-10 min. Parked it, let it cool down. And figure ill stop at autozone in the way to work and get the trouble codes pulled and give it time to cool down. Started truck up and it idled perfect, no issues. As soon as I went into reverse I got a misfire. On the way to the gas station It was misfiring so bad I had to pull over, when i pulled over the heavy misfiring slowed down but came back during acceleration. I was low on gas so I stopped and put 91 octane thinking maybe bad gas. Leaving gas station the truck idled fine and drove fine and got up to 45MPH no issues until i took foot off the throttle. As soon as my foot came off the throttle it was misfire very bad again, engine was chuging horible. I get to autozone and had codes pulled.
Dont have to code number infront of me( im at work currently codes are at home) but i do remember what they were:
Cylinder 5 misfire
Bank 2 Cam sensor
Bank 1 Cam over advanced
Bank 2 cam Over retarded
Bank 2 O2 sensor 1 stuck rich

All the COPs are new 2 years ago (Accel) Plugs were new 2 years ago (champion, I need to replace with motorcraft i know), The FPDM is new 2 years ago. VCT solinods are new last year. Fuel filter new last week.
*side note- last year my cylinder 5 was misfiring and i took it oto the dealer and had them check it and they said the COP was good and it was a bad plug. So i replaced cylinder 5 with a motorcraft plug, and misfire went away.

So at autozone I bought a new Cam pos sensor, new OEM COP just incase, and a motorcraft plug incase the plug went bad again.... Replaced all in parking lot... no differance. I did research and figured cam phaser finally failed. So i bought new Phasers with gear, chains, guides, tensioner....
So i replace everything, got it back together today. Started it up and It started and idled perfect, no misses no ticks from the phasers. I let it idle for about 20 min because i was adding antifreeze and burping the system. All 20 min no issue at all. Reved the engine, No misfire. So I took it down the road and immediately felt a small misfire. came back home, placed in park and still missing(seems like only 1 cylinder) and tried figuring out what cylinder is mising but couldnt figure it out, seemed every time i disconnect the COP id hear the engine stumble. I disconnected the VCT to try and see if that helped and that didnt make a differance.


Any suggestions...

 

Are you still getting a CEL after doing all that work? If so get it scanned again. It sounds like you need to find out which cylinder is misfiring before going any further.

 

Have you checked the oil pressure?

The symptoms you describe could be caused by low oil pressure. It sounds like the ignition is pretty well sorted out unless the plugs are all completely shot.

The cam phasers rub off oil pressure and if it gets below 20 psi then cam timing can become erratic and could cause all of the symptoms you describe.

Put on a mechanical gauge and verify hot oil pressure at idle. Should be above 20 psi.

Keep us posted!