Gutless 2006 Lincoln Navigator 230k

[quantum]

Hello (posted again as other does not show),

Rather than post the problem and sit back and expect somebody else to tell me whats going on, I’m going to share my diagnosis and pictures etc and see if you’ll agree with my ‘logic’.

Vehicle:
2006 Lincoln Navigator, Triton 5.4 V8 with 6 speed transmission. 230k on the clock.

Code:
Lean on Bank 1

Problem:
Totally Gutless! On a hill it can barely stay above 60kmh. On flat it’s tolerable but gutless.

My Diagnoses so far:

Running a scan tool I have determined that Bank 2 is running within +-5% on both LTFT and STFT. The fuel rail pressure is a consistent 38 thru 42 psi. I have also looked at the voltage fluctuations on all 4 O2 Sensors and they all appear to be functional.

Because I see No problem with the fuel pressure I have eliminated anything back from the fuel rail. The fact that the problem is ONLY on one side (Bank 1) my focus is fully on the Passenger side of the engine.

I have NO misfires so far on bank 1, I’m therefore assuming that there is no coil problem (independent coils).

The correlation between RPM and the LTFT 1 is very close. As the RPM goes up, the LTFT goes up. I have seen it as high as 39%. Charts included below. Because the the FT goes up with the RPM I’m assuming that there is NO vac leak or manifold leak.

THE ONLY thing that currently makes sense to me is that one or more of the fuel injectors on the passenger side of the engine is not functioning very well. On Idle the LTFT and the STFT on bank 1 is OK. It shoots up on higher RPM and more are through MAF. See below, Video and Pics.

I’m hoping you guys can chime in on my logic and my diagnosis. Thanks

BELOW JUST SHOWS O2

VIDEO AT: (NOTE: Battery disconnected for 24hrs prior to this video) https://www.youtube.com/watch?v=-pWWpcNVnO0

[Author]

Posts