Mechanics

RUNS GREAT UNTIL POWER LOSS AT 3000 RPM. WHAT PROBLEM COULD CAUSE THIS SYMPTOM WITHOUT THROWING CODES??

2007 Lincoln Navigator • 137,000 miles

Truck otherwise runs smooth and strong. Replaced all coils, MAF, and fuel filter. Runs great at idle and lower rpm but hesitates and feels like it is starving for fuel or air once you hit over 3K. It only comes into play when accelerating to merge on freeway or to mash on the pedal to pass another car. I would like it to run properly above 3000 rpms too.
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Twgreenwood
February 19, 2012.



Have you had it scanned for soft codes, which won't cause the CEL to illuminate. Check the catalytic converter, it may be plugged.

Rivermikerat
Feb 19, 2012.
I got the same problem with a 2005 navigator. I ve replaced catalytic converters but there was no change. Please help

Tiny
Tanui
May 1, 2012.
Check your fuel psi @ idle and driving it should maintain 65 to 71 psi

Djcl
May 1, 2012.