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Dumb question about a possible intermittent fuel pump and O2 sensor data.
Hi All! I have a 1998 Lincoln Navigator 5.4 Auto 4x4.
I have an issue that I'm working through. While diving longer distances, 45ish minutes or more, the throttle cuts in and out for a second or two and comes back. I say throttle because it feels like you've taken your foot off the gas pedal, and moving the gas pedal has no effect.
I don't lose crank signal. MAF data is reasonable. TP sensor reads while moving the throttle while its cutting out. It has no codes and the only data I find suspect is both O2 banks flatline to zero while the power cuts out.
Everything points an intermittent fuel pump. Am I over thinking the O2? It would obviously be lean with no fuel.
I've done the Ford trick of swapping the fuel pump relay and horn relay. My leads aren't long enough to probe the pump while driving. I may be able to find a spot to clamp the feed wire, but it's so hard to replicate without a long drive.
Pressure is a little low, but the truck has plenty of power.
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