WRT fuel pressure, I'm getting a little suspicious of original fuel pumps on any of these 3.0L trucks that are 10-15 years old. Several folks have replaced the pump recently on Gen1 trucks. That, in combination with my own experience on the S/C'd engine makes me wonder if all of the older pumps should be higher than usual on the suspect list. Granted, an FMU places a higher demand on a pump, but the recent pump failures have my attention.

It's not easy to check fuel pressure on a 3.0L unless you have the rail adapter - and even if you do, it's not a quick test.... the upper plenum has to be removed to easily get to the test adapter location on the fuel rail. An alternate test might be to disconnect the fuel line in a convenient spot and apply constant power to the fuel pump.

Another possibility that I didn't mention is the fuel pressure regulator, which could be tested with the pump if the test adapter is used.

Frank