help me with my suv please

[Nate]

i have a 2003 ford expedition XLT 2wd with 100k on the clock and its got a strange problem sometimes on the highway the rpms will drop and the truck will stall out also sometimes it has a lack of power when you smash the gas and makes a CLUNK noise a very shady mechanic told me it was the fuel pump i checked the fuel pressure it was just fine its a 4.6 L 2v V8 motor and a 4 speed automatic transmission if anyone can help me out that would be awesome thanks 🙂

Topic

[Bill]

Fuel pumps can be intermittant. Is the check engine light on? has it been scanned for fault codes?

[Nate]

been scanned no codes at all no cel either

[dollman0]

I had a similar problem with a suburban a week after someone replaced the fuel pump with one from Advance Auto. It was a faulty fuel pump not delivering enough fuel.

Its possible the strainer boot is restricted and not allowing enough GPH and causing a lean condition on a hard pull, the same is true of the filter or a weak electric motor in the fuel pump.

I would check the fuel pump relay as that is also a possible cause of a voltage drop to the fuel pump. Bad contacts can cause an intermittent problem.

I don’t work on Fords but these are some things to consider.

[Bill]

If i was diagnosing that vehicle i would be driving it with a fuel pressure gauge on it as well as a scan tool to read fuel trims while it’s acting up.

[Author]

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