2001 tj jeep no fuel pressure at tank

a while? 1sec, 1min 1hr?



filter, packed,
where is gage sensor on rail.?
ever get a full tune up?:
the fsm is free here.
http://www.jeep4x4center.com/knowledge-base/index.htm?utm_source=cj#service
tj unlimited?
2 systems dead head or loop and is key to diagnosis.
looking now.,
49.2psi is spec, +-5 page 2 (so pump is good) but?/...
it is loop but no fuel pump reg at rail.
that is rail pressure not anywhere else.
at 44 you key off the pressure must hold for 1/2 min. or you fail
leak down test, (injector leaks or check ball in pump)
if the check ball fails it will take many key on to get full pressure
2 or 3 second pump runs, each key:?
see why?> unplug injectors see if leak down passes/?
all filters and socks in take, below pump

so it fails leakdown
the only way to find this is to block rail input. line,
if it still leaks tank drops
if it stops the injectors leak (for all those reasons)

the tank regulator has its own loop return feed back
so the rail really is a dead head, with one line there.

Hi.

Check the fuel filter and fuel pressure regulator. They are part of the same assembly and are located on top of the fuel pump. To replace the regulator # Disconnect fuel supply line at the Filter/Regulator nipple and releas locking spring tab (2 in diag.) on the regulator, then turn counterclockwise and pull out. To test regulator use a gauge like this in fuel lines:Pump Pressure Tester.
Pressure in 2003 should be 58psi (48 in 2001 engines). Pressure will drop of about ten psi when you start engine.

There is also an automatic shut down relay ASR. If problem is the ASR the pressure will go down when the relay cuts off power to pump. Read voltages and see if the problem is electrical first before going for the regulator.

Fuel Pump Removal & Installation To Remove:
WARNING
The fuel system is under constant pressure, even when the engine is off. This pressure must be released before servicing the fuel pump module.

1. Drain fuel tank and remove the tank.
2. Thoroughly wash and clean area around pump module to prevent contaminants from entering tank.
3. The plastic fuel pump module locknut is threaded onto fuel tank. Install special tool #6856 to fuel pump module locknut and remove locknut. The fuel pump module will spring up when locknut is removed.
4. Remove the module from fuel tank.

To Install:
CAUTION
Whenever the fuel pump module is serviced, the module gasket must be replaced.

1. Thoroughly clean locknut threads and mating fuel tank threads. Use a solution of soap and water. Do not use carburetor cleaner to clean threads.
2. Using new gasket, position fuel pump module into opening in fuel tank.
3. Apply clean water to locknut threads.
4. Position locknut over top of fuel pump module.
5. Rotate module until arrow is pointed toward front of vehicle (12 o'clock position). This step must be done to prevent float/float rod assembly from contacting sides of fuel tank.
6. Install special tool #6856 to the locknut.
7. Tighten the locknut to 55 ft-lb (74 Nm).
8. Rotate fuel filter/fuel pressure regulator until its fitting is pointed to 10 o'clock position.
9. Install the fuel tank.

Fuel Filter for 5.2 L Removal & Installation To Remove:


NOTE: The combination fuel filter and fuel pressure regulator is located on the top of the fuel pump module.

1. Before servicing the vehicle refer to the precautions at the beginning of this section.
2. Remove or disconnect the following:
   • The fuel tank
   • Any debris around the filter/regulator to prevent contaminants from entering the pump module
   • The fuel filter/regulator from its rubber grommet by twisting and pulling straight up CAUTION
     To prevent damage to the coiled fuel line, ensure the filter/regulator is not more than three inches from the fuel pump module.
     
     
     
   • The old fuel line clamp, by carefully cutting it ensuring not to damage the plastic fuel line (discard the clamp)
   • The plastic fuel line from the filter/regulator by gently pulling downward
   • The filter/regulator from the fuel pump module

To Install:

1. Install or connect the following:
   • A new clamp over the plastic fuel line
   • The filter/regulator to the fuel line NOTE: Rotate the filter/regulator in the fuel line until it is points toward the front of the tank.
     
   • The line clamp to the fuel line using special Hose Clamp Pliers number C-4124 NOTE: Do not use conventional side cutters to tighten this type of clamp.
     
   • The filter/regulator into the rubber grommet, pressing by hand
2. Rotate the filter/regulator until it points towards the front of the vehicle.
3. Install the fuel tank.
4. Check for fuel leaks.

i'm assuming you disconnected the fuel line and placed the line in a container to catch the fuel when observing the flow.

it might sound strange but i think there might be a leak in the tank coming from the fuel pump assembly. it's possible a tube or hose is broken on the assembly and the pump is just pumping the gas back into the tank.

there's flow because there is no pressure building up with the line disconnectedand the gas flows. when connected, pressure builds and blows out the break in the tube or hose.

The fuel pressure regulator is built in to the fuel pump


Fuel tank and fuel pump assembly—XG 300

1. Before servicing the vehicle, refer to the Precautions section.
   
2. Relieve the fuel system pressure.
   
3. Drain the fuel tank.
   
4. Remove or disconnect the following:
   
   • Negative battery cable
     
   • Fuel supply, return and vapor lines
     
   • Fuel fill and vent hoses
     
   • Fuel pump module connector
     
   • Fuel level sender connector
     
   • Fuel tank straps
     
   • Fuel tank
     
   • Fuel pump module
     

To install:

1. Install or connect the following:
   
   • Fuel pump module and torque the mounting bolts to 12–24 inch lbs. (1–3 Nm)
     
   • Fuel tank
     
   • Fuel tank straps
     
   • Fuel level sender connector
     
   • Fuel pump module connector
     
   • Fuel fill and vent hoses
     
   • Fuel supply, return and vapor lines
     
   • Negative battery cable
     
2. Fill the tank with fuel and check for proper fuel pump operation.
   

the fuel pump and fuel pressure regulator are 2 different parts, the regulator is on the engine the fuel pump inside the gas tank.

Yes, there is a fuel filter it will either be in the fuel line somewhere near the tank, usually on the frame rail, or, it may be a servicable part of the fuel pump assembly, also incorperating a fuel pump pressure regulator into it ($) I suggest that you remove and clean the idle air control near the tps on the throttle body. Don't turn the spindle end while cleaning and don't loose the "o" ring seal. It won't hurt to have codes checked either...it may save a bunch of "tail chasing".
good luck

The combination Fuel Filter/Fuel Pressure Regulator is located on the fuel pump module. The fuel pump module is located on top of fuel tank.

The filter/regulator may be removed without removing fuel pump module although fuel tank must be removed.

REMOVAL

1. Remove fuel tank. Refer to Fuel Tank Removal/Installation.
2. Clean area around filter/regulator.
3. Disconnect fuel line at filter/regulator. Refer to Quick-Connect Fittings for procedures.
4. Remove retainer clamp from top of filter/regulator. Clamp snaps to tabs on pump module. Discard old clamp.
5. Pry filter/regulator from top of pump module with 2 screwdrivers. Unit is snapped into module
6. Discard gasket below filter/regulator.
   1. Before discarding filter/regulator assembly, inspect assembly to verify that O-rings are intact. If the smallest of the two O-rings can not be found on bottom of filter/regulator, it may be necessary to remove it from the fuel inlet passage in fuel pump module.
   INSTALLATION
   
   1. Clean recessed area in pump module where filter/regulator is to be installed.
   2. Obtain new filter/regulator (two new O-rings should already be installed)
   3. Apply a small amount of clean engine oil to O-rings. Do not install O-rings separately into fuel pump module. They will be damaged when installing filter/regulator.
   4. Install new gasket to top of fuel pump module.
   5. Press new filter/regulator into top of pump module until it snaps into position (a positive click must be heard or felt).
   6. The arrow molded into top of fuel pump module should be pointed towards front of vehicle (12 O'clock position).
   7. Rotate filter/regulator until fuel supply tube (fitting) is pointed towards front of vehicle (12 O'clock position).
   8. Install new retainer clamp (clamp snaps over top of filter/regulator and locks to flanges on pump module).
   9. Connect fuel line at filter/regulator. Refer to Quick-Connect Fittings for procedures.
   10. Install fuel tank. Refer to Fuel Tank Removal/Installation.

WARNING: THE FUEL SYSTEM IS UNDER CONSTANT FUEL PRESSURE EVEN WITH THE ENGINE OFF. THIS PRESSURE MUST BE RELEASED BEFORE SERVICING FUEL TANK .

Two different procedures may be used to drain fuel tank (lowering tank or using DRB scan tool).

The quickest draining procedure involves lowering the fuel tank.

As an alternative procedure, the electric fuel pump may be activated allowing tank to be drained at fuel rail connection. Refer to DRB scan tool for fuel pump activation procedures. Before disconnecting fuel line at fuel rail, release fuel pressure. Refer to the Fuel System Pressure Release Procedure for procedures. Attach end of special test hose tool number 6541, 6539, 6631 or 6923 at fuel rail disconnection (tool number will depend on model and/or engine application). Position opposite end of this hose tool to an approved gasoline draining station. Activate fuel pump and drain tank until empty.

If electric fuel pump is not operating, tank must be lowered for fuel draining. Refer to following procedures.

FUEL TANK REMOVAL

1. Disconnect negative battery cable at battery.
2. Release fuel system pressure. Refer to the Fuel System Pressure Release.
3. Raise and support vehicle.
4. If Equipped: Remove fuel tank skid plate.
5. Remove 4 fuel hose shield mounting bolts and remove fuel hose shield from body.
   1. Remove fuel tank fill hose and vent hose clamps at fuel tank filler tube. Remove both hoses at fuel filler tube.
   2. Remove exhaust tailpipe heat shield mounting bolts and remove shield. CAUTION: To protect fuel tank from exhaust heat, this shield must reinstalled after tank installation.
   3. Place a hydraulic jack to bottom of fuel tank. WARNING: PLACE A SHOP TOWEL AROUND FUEL LINES TO CATCH ANY EXCESS FUEL .
      1. Disconnect fuel supply line from fuel extension line near front of fuel tank. Refer to Fuel Tubes/Lines/Hoses and Clamps. Also refer to Quick-Connect Fittings for procedures.
      2. Disconnect EVAP canister vent line near front of tank.
      3. Disconnect fuel pump module electrical connector (pigtail harness) near front of tank. Harness connector is clipped to body.
         1. Remove two fuel tank strap nuts. Position both tank support straps away from tank.
         2. Carefully lower right side of tank while feeding both fuel hoses through access hole in body. Fuel Tank Full And Not Drained Using DRB Scan Tool: To prevent fuel loss through hoses, keep left side of tank higher than right side while lowering. Do not allow hose openings to drop lower than top of tank.
         3. Continue lowering tank until clear of vehicle. Place tank on floor with left side (hose side) higher than right side
            1. Drain tank by removing fuel fill hose at tank. Fuel fill hose is largest of 2 hoses. Insert the drain hose (from an approved gasoline draining station) into hose opening. Drain tank until empty.
            2. If fuel pump module removal is necessary, refer to Fuel Pump Module Removal/installation for procedures.
            INSTALLATION
            
            1. If fuel pump module is being installed, refer to Fuel Pump Module Removal/installation for procedures.
            2. Install fuel fill/vent hoses to tank fittings. To prevent hose from kinking, rotate each hose until index mark on hose is aligned to index tang on fuel tank.
            3. Install hose clamps to hoses. Position clamps between index marks on each hose.
            4. Position fuel tank to hydraulic jack.
            5. Raise tank into position while guiding fuel fill and vent hoses into and through access hole in body.
            6. Continue raising tank until positioned to body.
            7. Attach two fuel tank mounting straps and mounting nuts. Tighten nuts to 10 Nm (90 in. lbs.) torque. Do not over tighten nuts.
            8. Install both fuel hoses to fuel fill tube. Tighten both retaining clamps.
            9. Position fuel hose shield to body. Install and tighten 4 mounting bolts.
            10. Connect fuel pump module pigtail harness electrical connector near front of tank.
            11. Connect fuel pump module supply line near front of tank. Refer to Quick-Connect Fittings for procedures.
            12. Connect EVAP hose near front of tank.
            13. Install exhaust tailpipe heat shield.
            1. Install fuel tank skid plate (if equipped).
            1. Lower vehicle and connect battery cable to battery.