QuestionHello Kevin,
I have a 2000-model Grand Cherokee which takes a long time to start when it has been stalled for some time. From this forum I learned that the problem most likely is in the fuel pump (fuel draining back to the tank from the fuel pipe). My question is, how do I replace/or check those o-rings or oneway check valve in the pump?
Thanks for the help, Timo
AnswerTHIS BULLETIN SUPERCEDES TECHNICAL SERVICE BULLETIN 14-06-00,
DATED SEP. 15, 2000, WHICH SHOULD BE REMOVED FROM YOUR
FILES. THIS IS A COMPLETE REVISION AND NO ASTERISKS HAVE
BEEN USED TO HIGHLIGHT REVISIONS.
SUBJECT:
Longer Than Normal Engine Crank Time Prior To Engine Start
OVERVIEW:
This bulletin involves the repair of the fuel pump module.
MODELS:
1999 - 2001 (WJ) Grand Cherokee
2001 (WG) Grand Cherokee
NOTE: THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH
A GASOLINE ENGINE.
SYMPTOM/CONDITION:
The customer may experience a longer than normal engine cranking time prior
to engine start. This condition may be caused by fuel pressure loss due to
a worn sealing ring within the fuel module.
NOTE: QUALITY ANALYSIS HAS REVEALED THAT A WORN SEALING RING IS THE
PRIMARY REASON WHY THE FUEL MODULE IS REPLACED FOR FUEL PRESSURE
LEAK DOWN. IT IS RECOMMENDED THAT THE SEALING RING BE REPLACED
BEFORE A FUEL MODULE ASSEMBLY REPLACEMENT IS ATTEMPTED.
DIAGNOSIS:
1. Start and run the engine. Verify normal fuel system pressure of 339
kPa +/- 34 kPa (49.2 psi +/- 5 psi).
2. Stop the engine. Verify that the fuel system pressure does not fall below
207 kPa (30 psi) in less than five (5) minutes.
3. If the fuel pressure does not fall below 207 kPa (30 psi) in less than five (5)
minutes, then the long crank time may not be due to the fuel system. Further
diagnosis must be made to the entire engine system.
4. If fuel pressure does fall below 207 kPa (30 psi) in less than five (5) minutes, then
refer to TSB 14-05-99 for additional fuel system diagnostic assistance.
5. If diagnosis determines that the cause of the fuel system pressure loss is due to the fuel
pump module, then inspect the fuel pump module part number label for its assembly
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build date code (Julian date). The part number label is affixed to the fuel pump module
wire harness (pigtail), near the electrical connector to the body wire harness.
6. Inspect the bottom row of numbers on the fuel module label and locate the module
build date code. Determine the date of build (Julian date) for the fuel module
assembly. The first two numbers in the date code indicate the calendar year (1998
= 98, 1999 = 99, 2000 = 00, 2001 = 01), and the remaining three numbers in the
code (1 to 365) represent the day of the calendar year (Fig. 1).
Fig. 1
7. If the module part label indicates that the fuel module assembly was built on or before
November 04, 1999 (Julian date of 99308), then a spacer must be used with the sealing
ring. The split washer in the repair kit is used as the sealing ring spacer.
NOTE: FAILURE TO USE THE SPLIT WASHER, AS A SPACER FOR THE
SEALING RING (WHEN REQUIRED), MAY CAUSE EXCESSIVE MOVEMENT
AND DAMAGE TO THE SEALING RING.
8. If the module part label indicates that the fuel module assembly was built after
November 04, 1999 (Julian date of 99308), then a spacer must NOT be used with
the sealing ring. The split washer in the repair kit can be discarded.
NOTE: SOME REPLACEMENT FUEL PUMP MODULES, BUILT AFTER NOVEMBER
04, 1999 (DATE CODE 99308), HAVE BEEN USED TO REPLACE FUEL MODULES
BUILT PRIOR TO NOV. 04, 1999. IT IS IMPORTANT THAT PRIOR TO EACH REPAIR
THE MODULE DATE CODE BE PROPERLY DETERMINED.
9. An ALTERNATE METHOD to determine whether a spacer is required is to
measure the width of the sealing ring gland (Fig. 2).
a. Apply sufficient pressure to hold the poppet firmly in place on top of the fuel outlet
port. To prevent an incorrect measurement, the applied pressure must be on-center.
The poppet can easily tip up if an off-center force is applied to it.
b. Carefully measure the width of the sealing ring gland.
c. If the gland width is between 3.0 and 3.5 mm (0.118 to 0.138 in.), then
a spacer is not required to be installed.
d. If the gland width is 4.0 mm (0.157 in.) or greater, then a spacer is required
to be installed prior to the installation of the new sealing ring. The sealing
ring spacer is 1 mm (0.394 in.) in thickness and is used to prevent excessive
movement (wear) of the sealing ring in the gland.
-3- 14-002-01
Fig. 2 MEASURING GLAND WIDTH
1 - SEALING RING GLAND
2 - POPPET
3 - ON-CENTER FORCE APPLIED
4 - MEASUREMENT REQUIRED TO DETERMINE GLAND WIDTH
5 - FUEL OUTLET PORT
PARTS REQUIRED:
Qty. Part No. Description
1 05019308AA Kit, Fuel Pump Module Repair
EQUIPMENT REQUIRED:
1 6856 Wrench, Fuel Module Locknut Spanner
1 5069 Kit, Pressure Test
1 6539 Adapter, Fuel Pressure (for 5/16" fuel lines)
REPAIR PROCEDURE:
NOTE: WHENEVER THE FUEL PUMP MODULE IS SERVICED, SPECIAL
CARE MUST BE TAKEN TO PREVENT ANY DAMAGE TO THE FUEL LEVEL
SENDING UNIT, OR TO THE FLOAT AND FLOAT ARM.
1. Remove the fuel pump module. Refer to the appropriate Grand Cherokee Service
Manual - Group 14 (Fuel), for detailed removal instructions. Clean any debris
from immediate area of the fuel module before removal.
2. Drain excess fuel from the fuel module assembly.
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3. Place the fuel module on a clean, flat surface (Fig. 3).
Fig. 3 FUEL MODULE ASSEMBLY
1 - PLASTIC TOP HALF
2 - GUIDE CHANNEL
3 - RETAINING CLIP
4 - PLASTIC STANDOFF SPACER
5 - LOWER HALF ALUMINUM HOUSING
6 - PART NUMBER LABEL
4. From the fuel module repair kit, p/n 05019308AA, locate the three plastic standoff
spacers. Each standoff spacer will be used as a tool to release three retaining clips. The
retaining clips secure the fuel module plastic top half to the lower half aluminum housing.
5. Slide a standoff spacer into each retaining clip guide channel. Each standoff
spacer should be inserted between the aluminum housing and the plastic retaining
clip. Insert each standoff spacer far enough into the guide channel so that
the retaining clips disengage from the aluminum housing.
NOTE: MAKE SURE THE PLASTIC STANDOFF SPACERS ARE FULLY INSERTED
INTO THE GUIDE CHANNELS AND ALL THREE RETAINING CLIPS HAVE BEEN
DISENGAGED FROM THE LOWER HALF ALUMINUM HOUSING.
6. With the three retaining clips disengaged, separate the plastic top
from the aluminum housing.
7. Remove the expansion spring from the plastic outlet tube of the fuel pump
(Fig. 4). The spring will be reused.
-5- 14-002-01
Fig. 4 SEALING RING DETAIL
1 - EXPANSION SPRING
2 - CYLINDRICAL BORE IN TOP HALF
3 - SEALING RING POSITIONED ABOVE SPACER
4 - PLASTIC FUEL OUTLET TUBE
5 - SPLIT WASHER AS SEAL SPACER (IF USED)
6 - LOWER HALF OF FUEL MODULE
7 - TOP HALF OF FUEL MODULE
NOTE: DO NOT DISCONNECT ANY INTERNAL MODULE WIRING
HARNESS CONNECTIONS.
8. With one hand, and using two fingers, pinch the black sealing ring. Squeeze
the sealing ring to one side of the plastic outlet tube so it can be removed using
your other hand. Remove and discard the old sealing ring.
NOTE: DO NOT USE ANY SHARP TOOL TO REMOVE THE OLD SEALING RING.
DAMAGE TO ANY AREA OF THE PLASTIC FUEL OUTLET TUBE GLAND MAY CAUSE
DAMAGE TO THE NEW SEALING RING OR OTHER SEALING PROBLEMS.
9. Use shop air to clean the plastic fuel outlet and around the gland. Clean
the cylindrical bore, located in the plastic top half. Inspect all mating
surfaces for damage, scratches, and debris.
10. If the fuel module assembly was built after November 04, 1999 (Julian date 99308),
then proceed to step 13. Do not install a spacer on these later built fuel modules.
11. Locate the plastic split washer in the repair kit. The split washer will be used to take
up the extra space in the sealing ring gland width on the plastic fuel outlet tube.
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12. If the fuel module was built on or before November 04, 1999 (Julian date 99308),
then slide the split washer around and onto the sealing ring gland. The spacer
must be positioned at the bottom, below the sealing ring.
NOTE: THE SPLIT WASHER IS INSTALLED CORRECTLY AS A SPACER
WHEN THE OUTER DIAMETER OF THE WASHER IS ALIGNED WITH THE
OUTER DIAMETER OF THE PLASTIC OUTLET TUBE.
13. Using the enclosed packet of special lubricant, lubricate the new sealing ring, its
gland area, and the mating cylindrical bore located in plastic top half. Save some
lubricant for later use. No other lubricant should be used.
Fig. 5 SEAL AND SPACER INSTALLED
1 - SEALING RING
2 - POPPET
3 - 1 MM SPACER (IF REQUIRED)
4 - FUEL OUTLET PORT
14. Install the new sealing ring over the top of the plastic fuel outlet tube. Make sure the
sealing ring does not twist during installation. Carefully work the sealing ring around the
plastic outlet tube and into the gland. Do not over stretch the sealing ring (Fig. 5).
NOTE: MAKE CERTAIN THAT THE SEALING RING HAS NOT TWISTED OR
BEEN STRETCHED EXCESSIVELY. INSPECT THE ENTIRE SEALING RING
AND SPACER (IF INSTALLED) FOR PROPER POSITIONING. THE SPACER
MUST BE AT THE BOTTOM, BELOW THE SEALING RING.
15. Lubricate the sealing ring again with lubricant from the packet.
16. Install the previously removed expansion spring over the plastic fuel outlet tube.
-7- 14-002-01
17. Carefully align the top half retaining clips to the guide channels in the aluminum
housing. Make certain that the cylindrical bore aligns with the plastic outlet tube.
18. Compress the plastic top half onto the aluminum housing until the retaining clips
have fully engaged the slots in the aluminum housing. Inspect each retaining
clip and the expansion spring for proper positioning.
19. Press the plastic top half of the fuel pump module down onto the aluminum housing
until the fuel module is in its fully collapsed position. When released, the top half of
the fuel pump module should freely rebound to its fully extended position.
20. Repeat step 19 twice. It is important that the module expands on
its own and does not bind.
21. Verify that the fuel pump module returns to its fully extended position. If not, the
top half must be removed, the sealing ring inspected, and additional lubricant
must be applied to the sealing ring and mating surfaces.
22. Inspect the fuel pump module filter for damage or contamination.
23. Install the fuel pump module-to-fuel tank seal to the fuel pump module.
24. Install the fuel pump module and the fuel tank. Refer to the appropriate Grand Cherokee
Service Manual - Group 14 (Fuel) for detailed installation instructions.
NOTE: IF THE FUEL PUMP MODULE AND/OR FUEL TANK-TO-FUEL PUMP MODULE
SEAL IS NOT INSTALLED CORRECTLY, THEN AN EVAPORATIVE SYSTEM LEAK MAY
OCCUR CAUSING A DIAGNOSTIC TROUBLE CODE (DTC) AND MIL ILLUMINATION.
25. Start and run the engine. Verify correct fuel system pressure of 339
kPa +/- 34 kPa (49.2 psi +/- 5 psi).
26. Stop the engine. Verify that the fuel system pressure does not drop below
207 kPa (30 psi) in less than five (5) minutes.
