Service slants

Motor,  May 2002  by Marcy, Thomas

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Jeep

Long crank time. Some 1999-2000 Grand Cherokees may exhibit abnormally long engine cranking periods. And the situation may gradually become worse. The problem may be due to low initial fuel pressure as the engine is cranked.

The low pressure may be caused by a worn O-ring in the fuel module assembly or by plastic contaminants that have entered the fuel pump. The pressure may drop more than 30 psi in less than five minutes. If the fuel pressure doesn't drop, then the long crank time may not be caused by the fuel system, and you must begin a full engine diagnosis.

If your diagnosis points to the fuel pump module, then check the label on the module (affixed to the wire harness pigtail) for the build date code (Julian date), which is the bottom row of numbers. The first two numbers indicate the calendar year (1998, 1999 or 2000) and the remaining three numbers (1 to 365) represent the day (see illustration).

If the date code falls on or between 98152 and 99308, then replace the fuel pump module kit with quad ring (Part No. 05019308AA). If the date code falls on or between 99309 and 00136, then replace the fuel pump module assembly (Part No. 05012380AB).

Be sure to clean the area before replacing parts. Also note that if the fuel pump module or fuel-tank-to-module seal is not correctly installed during this procedure, an evap system leak could occur Remove the module from the vehicle and drain excess fuel from the assembly

Next, put the module on a clean, flat surface. Use the three plastic standoff spacers from the new kit to release the three retaining clips that secure the plastic top half of the module to the lower half aluminum housing. Slide a standoff spacer into each guide channel for the retaining clip. Insert each spacer between the aluminum housing and the plastic retaining clip far enough into the guide channel so the retaining clips disengage from the aluminum housing.

With the three retaining clips disengaged, separate the plastic top from the aluminum housing. Next, remove the extension spring from the outlet tube of the fuel pump. The spring will be reused. Do not disconnect any wiring harness connections.

Now pinch the black quad ring. Squeeze it to one side of the outlet tube so you can remove it with your other hand. After you remove it, discard it. (Do not use any sharp tool to remove the quad ring.) Now, don safety glasses and clean the plastic fuel outlet and retaining groove with compressed air. Also clean the cylindrical bore, located in the plastic top half. Inspect all mating surfaces for damage, scratches and debris, and repair or clean as needed.

Now use the plastic split washer in the repair kit to take up the extra space in the quad ring's retaining groove on the plastic fuel outlet tube. Slide the washer onto the quad ring retaining groove. The white spacer installs correctly when the washer's outer diameter aligns with the outer diameter of the plastic outlet tube.

Next, using the enclosed packet of lubricant, coat the new quad ring, retaining groove and mating cylindrical bore located in the plastic top half. Save some lubricant for later use. Install the new quad ring over the top of the plastic fuel outlet tube, being careful not to twist it. Carefully work the ring around the tube, placing it into the retaining groove, but don't overstretch it. The quad ring should now be positioned above the split washer.

Now lube the quad ring once again with the lubricant, then reinstall the extension spring over the outlet tube. Carefully align the top-half retaining clips to the guide channels in the aluminum housing. Make sure the cylindrical bore aligns with the plastic outlet tube.

Press the top half onto the aluminum housing gradually until the retaining clips fully engage the slots in the aluminum housing. Then inspect each retaining clip and the extension spring.

Next, press the plastic top half of the fuel pump module down onto the aluminum housing until the fuel module sits in the fully collapsed position. When released, the top half of the module should freely rebound to the fully extended position. Repeat this check several times, making sure the module returns to its fully extended position. If it doesn't, remove the top half and apply additional lubricant to the quad ring and its mating surfaces.

Now check the module's filter for damage or contamination, and replace it, if necessary. Install the module-to-- tank seal to the fuel pump module. Lastly, reinstall the module to the tank. Verify correct fuel system pressure of 49.2 psi 5 psi. Make sure the pressure doesn't drop more than 30 psi in less than five minutes.

GM

No 3rd and 4th gear. Certain GM vehicles (full list below) with the HydraMatic 4T40-E or 4T45-E transaxle built before 11/1/99 may experience loss of 3rd and 4th gears. According to GM, this could be caused by the molded seal on the direct clutch piston assembly delaminating from the steel housing, causing the outer lip of the piston seal to cut or tear and preventing the direct clutch from applying properly.