fuel pressure

[ranger r]

I have a 98 ranger 4.0 5 speed and I recently put a new fuel pump in it. Well two actually. And after a few days it goes bad. I can't figure out why. At 2500 rpm it gargles and sounds like its flooded but it also won't bounce the rev limiter. The only code it throws it an o2 but I know that's now the problem here. Any suggestions?

 

[RonD]

'98 should have the returnless fuel system so needs 65psi at the rail.
Fuel pressure tester can be rented, and would tell you,
Pressure running, 60-70psi
Pressure engine off, no lower than 50psi and stable, i.e. doesn't continue to drop

3rd party fuel pumps can fail quickly, basically a quality control issue.
Have you hooked up the fuel pumps to 12volts to make sure it is the fuel pump that has failed and not the Fuel Pump Relay or inertia switch?

You can test for a leaking injector:
Engine warmed up and turned off.
Turn key on
Press gas pedal to the floor and hold it there
Try to start engine(leave your foot on the gas pedal)

Engine should turn over but NOT start, it shouldn't fire at all.

If it starts or fires you have fuel leaking into intake, either from an injector or the Pulse Damper's vacuum hose.

If you let up on the gas pedal it will start.

Key on, throttle wide open, sets "clear flooded engine" mode in computer, this turns off the fuel injectors but leaves spark on.