scattermaster
Member
Hello,
I have a 2000 expedition with the 5.0 motor. XLT. Standard suspension. 255K mi.
Fuel pressure runs at about 30 psi. If I disable the regulator it jumps to about 40 psi.
ALSO, the pressure dumps immediately to zero when I turn off the engine.
If i turn the key to on, but do not start the engine, the fuel pressure momentarily goes up then right back to zero.
I have looked into what the pressure should be and I get conflicting numbers. Some say it should be 45-55 psi, and others say 30 psi.
I already replaced the regulator with a Motorcraft (CM5296) and nothing changed. It's still regulates it at 30 psi and defeated it jumps to 40.
So, what do you think?
Do I need a new fuel pump assembly ? I looked at the Motorcraft one on RockAuto (PFS99) and they don't list pressure in the specs.
Does that pump max out at 40 psi too?
The truck runs but it seems like it would start better if the pressure was maintained.
thx,
Jim
I have a 2000 expedition with the 5.0 motor. XLT. Standard suspension. 255K mi.
Fuel pressure runs at about 30 psi. If I disable the regulator it jumps to about 40 psi.
ALSO, the pressure dumps immediately to zero when I turn off the engine.
If i turn the key to on, but do not start the engine, the fuel pressure momentarily goes up then right back to zero.
I have looked into what the pressure should be and I get conflicting numbers. Some say it should be 45-55 psi, and others say 30 psi.
I already replaced the regulator with a Motorcraft (CM5296) and nothing changed. It's still regulates it at 30 psi and defeated it jumps to 40.
So, what do you think?
Do I need a new fuel pump assembly ? I looked at the Motorcraft one on RockAuto (PFS99) and they don't list pressure in the specs.
Does that pump max out at 40 psi too?
The truck runs but it seems like it would start better if the pressure was maintained.
thx,
Jim
