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-   -   OEM Fuel Pump Module Study (

ronjenx 01-27-2013 08:15 PM

OEM Fuel Pump Module Study
The fuel filters for the JK are in the fuel pump module, and are listed as "not serviced",
which means they can't be changed without replacing the entire fuel pump module.
The same goes for the fuel pump and the pressure regulator.
I have not seen any forum traffic about the filters being the source of problems.
Here are some pictures to show how this is all put together.

1. Here is a view of the fuel pump module.
The top cover is what is clamped to the top of the tank.
The spring holds the fuel reservoir down onto the bottom of the tank.

2. This is a close-up of the fuel lever sensor.
There are two contacts that sweep up and down on the sensor board.

3. Here you can see the discharge filter/pump sitting in the reservoir.
What is visible is actually the discharge filter container.
The pump is in the center of the filter.
Some of the pressurized fuel is tapped off to be shot from a nozzle,
through a flapper type check valve, and into the bottom of the reservoir.
As the fuel is shot in, it brings fuel from the tank into the reservoir with it.
This keeps the reservoir full, ensuring a good supply of fuel for the pump to draw from,
even when the fuel level in the tank is below the top of the reservoir.
The jet of fuel may also create a swirling effect in the bottom of the reservoir which
keeps the surface of inlet filter clean.
It also ensures the pump is constantly bathed in "cool fuel", at least until the very end of the supply.

4. A look at the flapper valve in the bottom of the reservoir.
Fuel can check in, but it can never leave, (except through the pump).

5. Here is the pump/discharge filter housing. You can see the inlet filter at the bottom.
The pressure regulator is to the lower left.
Anything over 58 2 psi is dumped through the outlet at the bottom of the regulator, into the reservoir.
The large black line carries fuel out of the tank, and on to the fuel rail on the engine.
The little black line routes some of the pressurized fuel to the jet nozzle,
where it is sprayed into the bottom of the reservoir, bringing fuel from the tank with it.
This keeps the reservoir full.

6. Here is a view of the pump, inlet filter, and discharge port.

7. This is the discharge filter housing, upside down to show where the pump discharge port connects.
As you can see, the pressure regulator housing is molded into the filter housing.

This pump module is very easy to disassemble, change the parts, and reassemble.
As far as I know, there is no parts support. So, if anything needs replacing, the entire module must be changed.
I think an access panel should have been made in the tub floor so the module could be removed without draining and removing the tank.
I have seen that in other vehicles.

1222 01-27-2013 10:11 PM

Excellent write-up and pics as always.:thumbsup:

Too bad your Jeep is incapacitated at the moment.:laugh:

JLC08JK 01-27-2013 10:37 PM

Another great "Study" added to the F.A.Q. :tea:

Godholio 01-27-2013 11:25 PM

Great information! That answered most of my questions about the filter...I also didn't know the fuel pressure regulator is included as well (that's another thing I don't like about it).

thedirtman 02-02-2013 09:56 AM

Thanks for posting.

SubAtomicGenius 02-03-2013 05:29 AM

Awesome job once again, Ronjenx! Interesting stuff. :)

The time now is 11:09 AM.

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