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Rough idle, injectors replaced, HELP

2004 - 2008 F-150

Rough idle, injectors replaced, HELP

Old 10-03-2014, 03:38 AM
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Rough idle, injectors replaced, HELP


I have a 2006 Lincoln navigator 5.4l 3v

Truck is running really rough and eventually stalls if you try to drive in gear even 5 feet. Will idle and wont stall if not in gear but idles rough rough. can rev up if you bring it up slowly. Pings and knocks like a **** trying to though

Have following codes only even after multiple clears and testing they return

bank 1 to rich
Bank 2 to lean

Truck ran great started happening about 2 weeks ago which felt like a misfire here and there then i parked it for about a week while i was working came back and it was missing really bad and pinging and knocking and since has been just stuck tinkering with it to figure out the problem because cant drive.

Oil and filter changed with motor craft filter and 5w20. just did it but also do every 3200 miles. truck has only 82,000
Fuel filter just changed.

Fuel pressure key on engine off 48-55psi at rail via scanner
Key on engine running 38-40 psi at rail via scanner

Fuel trims at 1800rpm (when it can rev there)
LTFT1 -24.6%
LTFT2 29.7%

STFT1 -8.1%
STFT2 12.1%

ohm checked all coils and cleaned them completely as well spring spade and all.
Cleaned throttle body
Checked the MAF looks clean and nice
Cleaned PCV
installed new spark plugs (motorcraft) just today
removed and checked both vct solenoids today as well. Both screens on each were clean and in perfect shape and tested both solenoids on the bench and they both check ok and move freely.
Installed brand new fuel injectors today as well. (acts exactly the same)

Truck has 14.0V at 1000rpm.

With truck running I went under the hood and started unplugging injectors. At any rpm if I unplug any injector on the driver side engine really bogs down and almost stalls, on the passenger side if I unplug 1 or all 4 injectors it makes no difference it still runs the same. Coils are getting power. Also if I unplug the vct sensors still runs like crap one, the other, or both makes no difference.

i cleared the codes and pcm after each time testing different things to make sure as well. Using a maxidas ds708 scanner.

Visually and checked with propane around the intake and hoses..even removed radiator fan to test with propane for leaks to be sure...

I am thinking now maybe the cats are plugged somehow, pcm is bad, or O2 sensors....

just not sure since all injectors on passenger side do nothing different when unplugged or in....If i unplug coils though it does change but i know those are wired different and that will affect the others on the other bank....

If you have any input it would be greatly appreciated.

Old 10-04-2014, 09:05 PM
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Swap the coils from one side of the engine to the other to verify them. I'd be tempted to do a compression test.

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