Customer Satisfaction 98024 - Fuel Injection Pump Replacement

General Motors has decided that certain1999 Chevrolet and GMC W4 and W5 model vehicles equipped with 4HE1-TC engines may exhibit a condition in which the four fuel injection timing gear bolts may loosen or fatigue due to the torque of the crankshaft. If this were to happen while the vehicle was being operated, the vehicle could lose power to the engine and the vehicle would coast to a stop.

To prevent the possibility of this condition occurring, dealers are to replace the fuel injection pump assembly with a redesigned six bolt fuel injection pump assembly.

Involved are certain1999 Chevrolet and GMC W4 and W5 model vehicles equipped with a 4HE1-TC engine. The involved vehicles are listed below.

Important: Dealers should confirm vehicle eligibility through VISS (Vehicle Information Service System) or ServiceNet (GMC only) prior to beginning campaign repairs.

American Isuzu Motors, Inc. will contact all involved dealers to coordinate shipment of parts. DO NOT ORDER THIS PART FROM GMSPO.

There are two different types of injection pumps for the 4HE1-TC powerplant. These units were rated according to the engine horsepower output. After obtaining the part number from the current fuel injection pump assembly to be removed, use the table below to find the corresponding part number to the new replacement unit. Fuel injection pump assemblies will be supplied at no charge. Removed fuel injection pump assemblies are to be returned.

Customers will be notified of this campaign on their vehicles by General Motors (see copy of typical customer letter included with this bulletin - actual divisional letter may vary slightly).

All unsold new vehicles in dealers' possession and subject to this campaign MUST be held and inspected/repaired per the service procedure of this campaign bulletin BEFORE customers take possession of these vehicles.

Dealers are to service all vehicles subject to this campaign at no charge to customers, regardless of mileage, age of vehicle, or ownership, from this time forward.

Customers who have recently purchased vehicles sold from your vehicle inventory, and for which there is no customer information indicated on the dealer listing, are to be contacted by the dealer. Arrangements are to be made to make the required correction according to the instructions contained in this bulletin. This could be done by mailing to such customers a copy of the customer letter accompanying this bulletin. Campaign follow-up cards should not be used for this purpose, since the customer may not as yet have received the notification letter.

In summary, whenever a vehicle subject to this campaign enters your vehicle inventory, or is in your dealership for service in the future, please take the steps necessary to be sure the campaign correction has been made before selling or releasing the vehicle.

Important: A copy of the service procedure, with figures, will be included with parts shipped from American Isuzu Motors, Inc.

Inspection Procedure

Inspect the serial data plate for the part number.

Removal Procedure

1. Before tilting the cab, rotate the idle control knob at the dash panel to the "minimum" position (counterclockwise).
2. Disconnect the negative battery cable.
3. Turn the crankshaft until the timing mark on the crankshaft damper pulley is aligned at 13 degrees BTDC for the No. 1 cylinder.
4. Remove the timing inspection plug from the side of the fuel injection pump.
5. Confirm that the 13 degree mark comes to position in the injection pump timing inspection hole.
6. Remove the intake air duct.

Important: Mark the vacuum hoses before they are disconnected. Improper position may lead to driveability problems.

7. Remove the vacuum control panel.
8. For vehicles with automatic transmissions, remove the bolt from the automatic transmission fluid filler tube bracket. Move the automatic transmission fluid filler tube in order to gain access to the oil level guide tube bracket bolt.
9. Remove the engine stop cable from the injection pump lever.
10. Remove the throttle lever assembly and the cables. Do not loosen any adjusting fasteners.
11. Remove the dipstick tube.

Remove the dipstick tube fixing bolt and pull out the dipstick.

12. Disconnect the harness to the engine speed sensor.
13. Remove the engine speed sensor in order to prevent damage during injection pump removal.
14. Place a pan underneath the fuel pump to catch some of the fuel that will be released during the next procedure.
15. Disconnect the fuel return hose.

Important: In order to prevent the unnecessary release of fuel, plug the fuel hoses from the fuel tank after disconnection.

16. Disconnect the fuel hoses.
17. Remove the fuel line fixing clamps.
18. Remove the L-shaped inlet line from the feed pump.
19. Remove the mounting bracket for the fuel line fixing clamps.

Important: In order to avoid bending the lines during removal, use a 19 mm open-ended wrench to support the base of the threaded outlet port while removing the banjo bolt.

Mark this bolt for this location since this bolt CANNOT be interchanged.
20. Remove the banjo bolt from the fuel line that leads from the feed pump to the fuel filter assembly.

Important: Mark this bolt for this location since this bolt CANNOT be interchanged.

Be sure to keep contaminants away from this bolt as they may clog the injectors after installation.
21. Remove the banjo bolt from the fuel line that leads from the fuel filter assembly to the injector pump.
22. Remove the check-valved banjo bolt from the fuel return line.

Important: Use extreme care when removing the fuel filter assembly in order to prevent bending of the fuel lines.

23. Remove the fuel filter assembly with the lines attached.

Important: Use extreme care when disconnecting the oil supply line in order to prevent bending of the oil line.

24. Disconnect the oil supply line.
25. Disconnect and remove the return hose from the PCV breather canister.
26. Remove the blue injection line fixing clamps that are attached to the intake plenum.

Important: Do not apply excessive force to the injection lines.

27. Disconnect and remove the injection lines from the injection pump and the injectors.
28. Disconnect the aneroid/boost compensator control hose.

Important: Do not pull on the harness with excessive force.

29. Disconnect the MI-TICS harness connection.
30. Remove the intake plenum in order to gain additional clearance.
31. Remove the injection pump assembly.

There is a support bracket on the bottom on the injection pump assembly.

Installation Procedure

1. Install the two tamper-proof caps to the NEW replacement injection pump unit.

Important: Do not discard the rubber caps and the sleeves. The sealing caps and the sleeves will be reused for the shipping of the core unit.

2. Remove and retain the rubber caps and the sleeves from the new pump.
3. Remove the L-shaped inlet line from the feed pump in order to ease pump installation.
4. Remove the timing inspection bolt from the replacement injection pump unit.
5. Install a new O-ring to the injection pump housing bracket.
6. Align the injection pump timing mark with the timer slit. Use a suitable tool to accurately align the two marks before installing the pump unit.
7. Install the replacement injection pump assembly.

Tighten

•	Tighten the 14 mm injection pump mounting fasteners to 48 N·m (35 lb ft).

•	Tighten the 17 mm injection pump mounting fasteners to 72 N·m (53 lb ft).

8. After mounting, make sure that the 13 degree mark is in position through the injection pump timing inspection hole.
9. Install the bottom injection pump bracket.

Tighten
Tighten the pump bracket fasteners to 28 N·m (20 ft lb).

10. Turn the crankshaft until the timing mark on the crankshaft damper pulley is aligned with the 8 degrees BTDC.
11. Confirm that the 8 degree mark comes to position in the injection pump timing inspection hole.
12. Install the timing inspection plug.
13. Connect the MI-TICS harness.

Be sure to attach the support clip of the bracket to the harness connector. The wire harness hold-down tab from the old pump unit must also be re-used.

Important: There are several wire harness hold-down tabs that must be secured with the mounting bolts.

14. Install the intake plenum.

Tighten
Tighten the mounting bolts to 20 N·m (15 lb ft).

15. Insert the bottom half of the blue injection line fixing clamps on the threaded mounting studs.
16. Install the fuel injection line assembly and hand-tighten the injection pipe sleeve nuts.

Important: Make sure that the clamps are in their original position. Improper placement will result in injection line breakage and fuel pulsing noise.

17. Install the top half of the injection line fixing clamps.

Tighten
Tighten the mounting nuts to 3 N·m (26 lb in).

18. Tighten the injection pipe sleeve nuts.

Tighten
Tighten the nuts to 29 N·m (22 lb ft).

19. Install the return hose to the PCV breather canister.

Important: Use extreme care in order to prevent bending of the oil supply line. Do not apply excessive force to the injection pump oil supply line.

20. Install the injection pump oil supply line with the new sealing washers.

Tighten
Tighten the banjo bolts to 17 N·m (12 lb ft).

21. Install the fuel filter assembly.

Tighten
Tighten the bracket bolts to 34 N·m (25 lb ft).

22. Install the two fuel line bracket attachment bolts near the serial data plate of the injection pump.

Tighten
Tighten the bolts to 17 N·m (12 lb ft).

23. Position the fuel return line in place. Install the check-valved banjo bolt with new sealing washers.

Tighten
Tighten the bolt to 23 N·m (17 lb ft).

Important: The banjo bolts must be in their proper position.

24. Place two fuel line banjo bolts side-by-side.
25. Position the fuel line that leads from the feed pump to the fuel filter assembly. Install bolt A (smaller center passage) with new sealing washers.

Tighten
Tighten the bolt to 23 N·m (17 lb ft).

26. Position the fuel line that leads from the fuel filter assembly to the injection pump. Install bolt B (larger center passage) with new sealing washers.

Tighten
Tighten the bolt to 23 N·m (17 lb ft).

27. Install the mounting bracket for the fuel line fixing clamps.
28. Install the L-shaped inlet at the feed pump.

Important: There must be a white plastic filtering screen inside this banjo bolt.

Tighten
Tighten the banjo bolts to 41 N·m (30 lb ft).

29. Install the fuel line fixing clamps.
30. Connect the fuel feed hose. Remove any plugs.
31. Connect the fuel return hose.
32. Install the engine speed sensor and connect the harness.

Tighten
Tighten the engine speed sensor mounting bolt to 5 N·m (48 lb in).

Important: Replace the two orange O-rings before insertion into the engine block and verify that the guide tube is completely inserted in the engine block. Make sure that the attachment bolts are in the proper positioned and tightened to 13 N·m (113 lb in).

33. Install the dipstick tube.
34. Install the throttle lever assembly and the cables.

Tighten

•	Tighten the attachment bolts to 19N·m (14 lb ft).

•	Tighten the remaining attachment bolts of the dipstick tube to 13N·m (113 lb in).

35. Install the engine stop cable.
36. For vehicles with automatic transmissions, install the automatic transmission fluid filler tube fixing bolt.

Tighten
Tighten the bolt to 13N·m (113 lb in).

Important: Be sure to connect the vacuum hoses to their original position. Improper position may lead to driveability problems.

37. Install the vacuum control panel.

Tighten
Tighten the chassis attachment bolts to 19N·m (14 lb ft).

38. Connect the control harness.
39. Install the intake air duct.
40. Connect the battery ground cable.
41. Perform the Fuel System Air Bleed procedure.

Bleeding the Fuel System

Whenever the fuel system is opened to the atmosphere, outside air can enter. Trapped air in the fuel system will cause the engine to run poorly. After performing any service that requires opening of the fuel system, all trapped air must be removed by bleeding the fuel system.

1. Loosen the bleed screw on the injection pump.
2. Pump the primer pump until the fuel flow is free of air bubbles from the bleed screw.

Twist the pump knob to release the primer pump handle. Push down and tighten to close the knob.

Some fuel may flow out after all the trapped air has escaped.

3. Tighten the bleed screw and close and the primer pump knob.
4. Start the engine and inspect for any leaks during operation. Correct any leaks as needed.
5. Place the Service Completion ID on the housing of the new injection pump.

Placement of Service Completion ID

As an easy identifier to show that the criteria of the campaign has been met, mark the NEW injection pump housing on the vehicle with the red dot using a RED marking.

Important: Vehicles not affected by this campaign bulletin also do not have the red dot. The markings are primarily used to identify the affected vehicles (early production only), after the above service procedures were performed.

1. Install the GM Campaign Identification Label.
2. Away from the vehicle, drain excess fluids from the REMOVED core pump (refer to the following procedures.

Draining Residual Fuel/Oil Before Shipping Pump

Due to environmental and safety issues, the remaining fuel and oil must be properly drained from the removed injection pump assembly prior to repackaging for return shipment.

Important: The remaining parts on the removed injection pump assembly are to be returned undamaged. Do not drop the unit on the ground or lift by its delicate components. A core charge will be accessed for the return of damaged or unsalvageable units.

1. Lift the pump assembly above the drain pan while draining.
2. With a shop towel, wipe away excess fluids from the injection pump housing.
3. Follow the return instructions from the removed injection pump assembly.

Return Instructions for Injection Pump Assembly

Important: Core returns must be properly shipped within 24 hours.

1. Reinstall the fuel and the oil fittings to the pump (as delivered with the new pump).
2. Install the L-shaped inlet line to the feed pump at its "shipping" position. The L-shaped line MUST be mounted upwards so that it will not be damaged during shipping.
3. Use the supplied sleeves and the caps from the new pump and CAP ALL CONNECTIONS.
4. Install the throttle return springs, if removed.
5. Cover and seal the pump unit from moisture with the supplied heavy gauge vinyl wrap.

Important: Take care so as not to damage the pump. Contents MUST be secure in the shipping container in order to prevent unnecessary damage during transport.

6. Secure the pump in the ZEXEL reusable container using the same method as delivered.
7. Affix the return labels over the existing labels on the top of the lid and the front side of the container.
8. Contact AIT Freight Systems at 1-800-433-7931 in order to arrange for OVERNIGHT return shipment. Inform AIT Freight Systems that this is under the Zexel program.

Each vehicle corrected in accordance with the instructions outlined in this Product Campaign Bulletin will require a "Campaign Identification Label". Each label provides a space to include the campaign number and the five (5) digit dealer code of the dealer performing the campaign service. This information may be inserted with a typewriter or a ball point pen.

Each "Campaign Identification Label" is to be located on the radiator core support in an area which will be visible when the vehicle is brought in by the customer for periodic servicing. When installing the Campaign Identification Label, be sure to pull the tab to allow the adhesion of the clear protective covering. Additional Campaign Identification Labels can be obtained from VISPAC Incorporated by calling 1-800-269-5100 (Monday-Friday, 8:00 am to 4:30 pm Eastern Standard Time). Ask for Item Number S-1015 when ordering.

Apply the "Campaign Identification Label" only on a clean, dry surface.

Submit a Product Campaign Claim with the information indicated below. Refer to the General Motors Corporation Claims Processing Manual for details on Product Campaign Claim Submission.

Dear Chevrolet/GMC Customer:

This notice is sent to inform you of a recall campaign that includes your vehicle.

General Motors has decided that CERTAIN 1999 Chevrolet and GMC W4 and W5 model vehicles equipped with 4HE1-TC engines may exhibit a condition in which the four fuel injection timing gear bolts may loosen or fatigue due to the torque of the crankshaft. If this were to happen while the vehicle was being operated, the vehicle could lose power to the engine and the vehicle would coast to a stop.

To prevent the possibility of this condition occurring, your GM dealer will inspect the fuel injection pump assembly, and if necessary, replace the assembly with a redesigned six bolt fuel injection pump assembly. This service will be performed for you at no charge .

Please contact your dealer as soon as possible to arrange a service date and to assure parts availability. Instructions for making this correction have been sent to your dealer. Please ask your dealer if you wish to know how much time will be needed to schedule, process, and repair your vehicle.

If you experience any trouble scheduling your vehicle or you have any questions regarding this recall action, please contact the appropriate Customer Assistance/Relations Center at the number listed below:

The enclosed customer reply card identifies your vehicle. Presentation of this card to your dealer will assist in making the necessary correction in the shortest possible time. If you no longer own this vehicle, please let us know by completing the postage paid reply card and returning it to us.

We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our products.

Chevrolet/Pontiac-GMC Division

General Motors Corporation

Enclosure

Dear GMC Customer:

This notice is sent to inform you of a recall campaign that includes your vehicle.

General Motors has decided that CERTAIN 1999 Chevrolet and GMC W4 and W5 model vehicles equipped with 4HE1-TC engines may exhibit a condition in which the four fuel injection timing gear bolts may loosen or fatigue due to the torque of the crankshaft. If this were to happen while the vehicle was being operated, the vehicle could lose power to the engine and the vehicle would coast to a stop.

To prevent the possibility of this condition occurring, your GM dealer will inspect the fuel injection pump assembly, and if necessary, replace the assembly with a redesigned six bolt fuel injection pump assembly. This service will be performed for you at no charge .

Please contact your dealer as soon as possible to arrange a service date and to assure parts availability. Instructions for making this correction have been sent to your dealer. Please ask your dealer if you wish to know how much time will be needed to schedule, process, and repair your vehicle.

If you experience any trouble scheduling your vehicle or you have any questions regarding this recall action, please contact the appropriate Customer Assistance/Relations Center at the number listed below:

The enclosed customer reply card identifies your vehicle. Presentation of this card to your dealer will assist in making the necessary correction in the shortest possible time. If you no longer own this vehicle, please let us know by completing the postage paid reply card and returning it to us.

We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our products.

Pontiac-GMC Division

General Motors Corporation

Enclosure

Dear Chevrolet Customer:

This notice is sent to inform you of a recall campaign that includes your vehicle.

General Motors has decided that CERTAIN 1999 Chevrolet and GMC W4 and W5 model vehicles equipped with 4HE1-TC engines may exhibit a condition in which the four fuel injection timing gear bolts may loosen or fatigue due to the torque of the crankshaft. If this were to happen while the vehicle was being operated, the vehicle could lose power to the engine and the vehicle would coast to a stop.

To prevent the possibility of this condition occurring, your GM dealer will inspect the fuel injection pump assembly, and if necessary, replace the assembly with a redesigned six bolt fuel injection pump assembly. This service will be performed for you at no charge .

Please contact your dealer as soon as possible to arrange a service date and to assure parts availability. Instructions for making this correction have been sent to your dealer. Please ask your dealer if you wish to know how much time will be needed to schedule, process, and repair your vehicle.

If you experience any trouble scheduling your vehicle or you have any questions regarding this recall action, please contact the appropriate Customer Assistance/Relations Center at the number listed below:

The enclosed customer reply card identifies your vehicle. Presentation of this card to your dealer will assist in making the necessary correction in the shortest possible time. If you no longer own this vehicle, please let us know by completing the postage paid reply card and returning it to us.

We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our products.

Chevrolet Motor Division

General Motors Corporation

Enclosure