General Motors of Canada Limited has determined that certain 1992, 1993 and 1994 W5-W7 Series may experience erosion in the fuel injection pump housing. Analysis has shown erosion to be the result of cavitation in the fuel injection pump housing. Erosion could eventually allow diesel fuel to leak into the engine crankcase causing oil dilution.
o increased crankcase oil levels
o Decrease in fuel economy
o Poor acceleration
To correct this condition, the fuel injection pump and fuel retum pipe will need to be replaced. In addition, if the vehicle did not have a fuel pipe modification completed from Product Campaign Bulletin 2N20, dated November 1992, the modification will also need to be completed at this time and is included in the labour time allowance of this bulletin. Dealers are also required to complete an oil and oil filter (vehicle is equipped with two oil filters) change free of charge to the customer. This oil and filter change is only valid at time of fuel injection pump replacement under this product campaign and is also included in the labour time allowance of this bulletin.
Involved are certain 1992, 1993 and 1994 GMC Forward W5-W7 Series built within the following VIN breakpoints:
1992 W5 Kawasaki 3 N3000003 N3002274 W7 N3200004 N3202284
1993 W5 Kawasaki 3 P3000001 P3002275 W7 P3200002 P3202219
1994 W5 Kawasaki 3 R3000011 R3001399 W7 R320001 R3200844
All affected vehicles have been identified by the VIN listing provided to involved dealers with this bulletin. Any dealer not receiving a listing was not shipped any of the affected vehicles.
All unsold new vehicles in dealer's possession and subject to this campaign MUST be held and inspected/repaired per the Service Procedure of this Campaign Bulletin before owners take possession of these vehicles.
Dealers are to perform this campaign on all involved vehicles at no charge to owners, regardless of kilometers traveled, age of vehicle, or ownership, from this time forward. However, due to limited fuel injection pump availability, the unsold vehicles will be done first and then the vehicle owners will be notified by staggered mailing dates every 3 months, starting with the newest vehicles (1994) first.
Owners of vehicles recently sold from your new vehicle inventory with no owner information indicated on the dealer listing, are to be corrected by the dealer, and arrangements made to make the required correction according to instructions contained in this bulletin. This could be done by mailing to such owners a copy of the owner letter accompanying this bulletin. Campaign follow-up cards should not be used for this purpose, since the owner may not as yet have received the notification letter.
In summary, whenever a vehicle subject to this campaign is taken into your new or used 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.
Refer to Section 4 of the Service Policies and Procedures Manual for the detailed procedure on handling Product Campaigns. Dealers are requested to complete the campaign on all transfers as soon as possible.
Owners will be notified of this campaign on their vehicles by General Motors (see copy of owner letter included with this bulletin) according to staggered mailing dates due to limited parts availability. A listing of owner name and addresses has been furnished to the involved dealers to enable dealers to follow up with owners involved in the campaign. The listing provided is for campaign activity only and should not be used for any other purpose.
Parts required to complete this campaign should be ordered through regular channels, as follows:
Part Number Description Quantity/Vehicle ------------------------------------------------------------------ * NPN Fuel Injection Pump 1
25011902 Oil Filter, Main 1
94054123 Oil Filter, By Pass 1
* Injection Pump Assembly kits must be ordered through Technical Assistance Center - Group Number 4. When ordering replacement fuel injection pump from TAC, dealers should notify TAC if pump is for a new unsold vehicle
1. Reinstall the fuel and oil fittings to the pump and cap all connections.
2. Reinstall throttle return springs and tubes (if removed).
3. Secure pump with four (4) hex nuts (refer to Figure 12, Item A).
4. Affix return labels over existing labels on top of lid, and front side of container (refer to Figure 12, Item B).
5. Contact the original shipping courier and return injection pump freight prepaid, by ground transportation, to Repair Center.
6. Place all documents in envelope and return with pump. (Include a legible copy of Repair Order with TAC Case Number noted on Repair Order.)
Credit for the campaign work performed will be paid upon receipt of a properly completed campaign claim card or DCS transmission in accordance with the following:
* Time Repair Code Description Allowance ------------------------------------------------------------------------- 2A Remove and replace W5 fuel injection 4.6 hrs. pump w/automatic transmission (includes oil and oil filter change)
3A Remove and replace W5 fuel injection 4.4 hrs. pump w/manual transmission (includes oil and oil filter change)
4A Remove and replace W7 fuel injection 4.1 hrs. pump w/automatic transmission (includes oil and oil filter change)
5A Remove and replace W7 fuel injection 3.9 hrs. pump w/manual transmission (includes oil and oil filter change)
* Above labour time includes: Injection pump remove and replace, change engine oil and filters, install new fuel return line and install transfer pump fuel line (if necessary) and 0.1 hour for dealer administrative detail associated with this campaign.
An allowance of $150.00 for the handling of the injection pump + 14 liters of engine oil is included in all repair codes.
FUEL INJECTION PUMP REMOVAL
1. Park vehicle, position selector lever in neutral, turn key to off position, exit tilt cab, position safety pin and block the front wheels.
2. Make sure fuel shut off lever (Figure 1, Item B) is in the stop position (forward position), pointing toward front of vehicle.
3. Disconnect negative battery cable.
4. Rotate crankshaft clockwise until the timing indicator on engine case lines up with the 20 degrees BTDC mark on the balancer (Figure 2). The mark on the pump flywheel and indicator on housing should line up at this point (Figure 3, Item D).
5. Disconnect injection pump wire harness at injection box.
6. Remove air inlet pipe to air cleaner assembly.
7. Remove power steering unit reservoir at frame rail and secure unit.
8. Remove passenger side mud flap. (W5 driver side and passenger side must be removed as well as the cab cross member support.)
9. Remove or loosen 12 mm bolt holding transmission cable(s) from the bracket and push cables aside out of the way. Remove two (2) 12 mm bolts holding transmission cable to manifold.
10. Remove cotter pin and washer from stop cable bracket and throttle cable bracket, remove cables, replace pins and washers to studs.
11. Remove air compressor inlet line.
12. Clamp off both fuel lines from fuel tank, underside of engine.
13. Remove twelve (12) fuel return lines at injection pump.
14. Remove fuel line jaw clamps from all fuel lines (Figure 4).
15. Loosen all fuel lines. Do not remove eye bolts at this time.
16. Remove two (2) 10 mm bolts securing fuel line bracket to manifold holding fuel lines to filter. Loosely replace bolts to manifold.
17. Remove fuel lines, reinstall eye bolts to their original locations.
18. Loosen injector lines at the injection pump and the fuel injectors.
19. Remove injector lines from engine.
20. Remove turbo boost line.
21. Remove oil cooler lines.
22. Loosen bolt on injection pump coupling jaw using a 19 mm open end wrench. Back out bolt far enough to free bolt from coupling to injection pump, rotate coupling 180 degrees by turning altenator pulley, loosen other bolt on coupling, again back out far enough to free bolt from coupling to injection pump, rotate coupling and engine pulley until timing marks again line up.
23. Remove four (4) bolts holding injection pump to mount and discard.
24. Remove remaining 14 mm bolts holding injection pump bracket to engine. A 14 mm socket and breaker bar may be required, using a medium size screwdriver to pry bracket off pins on side of engine.
25. Injection pump may be removed.
1. Install four (4) NEW 12 mm bolts to secure injection pump to mounting bracket. Torque 12 mm bolts to 20 ft/lbs or 27 N.m (Figure 5, Item B). Insure bracket is properly set on locator pins. Torque 14 mm bolts to 25 ft/lbs or 34 N.m (Figure 5 Item C).
2. Install rear of pump first and align to coupling jaw, center injection pump on mounting bracket and move pump up and down in order to start the 19 mm coupling bolts.
3. Torque two (2) 19 mm coupling bolts to 65 ft/lbs or 88 N.m (Figure 8. Item K.)
4. Install small oil cooler line to injection pump, oil filter, and air compressor. Torque all three 12 mm bolts to 20 ft/lbs or 27 N.m (Figure 8. Item B).
5. Install larger oil line to injection pump and engine. Torque oil cooler line 25 ft- lbs or 34 N.m and the oil line to injection pump to 29 ft/lbs or 39 N.m (Figure 8. Item C and D).
6. Reinstall or install fuel inlet pipe to transfer pump. Torque to 29 ft/lbs or 39 N.m (Figure 8 Item D), Refer to Product Campaign Bulletin 92-N-20 if necessary.
7. Install turbo boost line. Torque to 20 ft/lbs or 27 N.m (Figure 8, Item E).
8. Install all fuel injection lines from injection pump to fuel injectors. Torque all six (6) lines at injection pump to 22 ft/lbs or 30 N.m and all six (6) lines to injectors to 29 ft/lbs or 39 N.m. It will be necessary to use a 6" extension and 17 mm crows foot (Figure 8, Items F and G).
9. Install the new fuel return line to the injection pump (WS part is #1-154-15720-0. W7 part is #1-154-15719-0. Torque eye bolt at injection pump to 29 ft/lbs or 39 N.m (Figure 8 Items D and F).
10. Remove vise grip pliers from fuel tank hoses.
11. Loosely install fuel pipes to injection pump, transfer pump, and fuel filter. Properly position wire harness between fuel pipes. Torque the 17 mm bolts at injection pump, transfer pump and steel colored bolt at the fuel filter to 29 ft/lbs or 39 N.m (Figure 8, Item D). Leave the outlet line at the top of fuel filter loose at this time. This bolt will be torqued after bleeding procedure (Figure 7, Item C).
12. Install all jaw clamps to fuel lines (Figure 4).
13. Install pipe to air compressor and position rubber hoses and hose clamps.
14. Remove cotter pins and washers from throttle cable stud and run stop lever stud, position throttle cable over studs and reinstall washers and cotter pins.
15. Install two (2) 12 mm bolts holding cable bracket to intake manifold. DO NOT OVER TIGHTEN THESE BOLTS.
16. Install power steering reservoir to frame.
17. Remove protective inserts from new wire harness connectors and connect the gray and black connectors on wire harness.
18. Install black turbo pipe.
19. Connect negative battery cable to battery.
20. Check to ensure all fuel lines are properly connected.
21. Bleed the fuel system to remove any air which has entered the system.
a) Unscrew the primer knob at the transfer pump and lift it up (Figure 7, Item B), also loosen bolt on top of fuel filter (Figure 6, Item B).
b) Pump the pump knob until a solid stream of fuel comes out of the fuel outlet line at top of fuel filter. Torque the fuel outlet fitting at top of fuel filter to 29 ft/lbs or 39 N.m (Figure 6. Item B).
22. Clean any spilled fuel from engine area.
23. Attempt to start engine. If the engine does not start within the first several engine cranks, stop and repair the bleeding procedure and attempt to start engine again. Once engine starts, slowly engine rpm's to force fuel into engine.
24. Complete oil and filter change. Oil filter part numbers are 25011902 and 94054123.
25. Check engine for fuel leaks and correct as required.
26. Install "Campaign Identification Label" to the inside of the driver's door pillar.
Clean surface of driver's door pillar and apply a Campaign Identification Label. Make sure the correct campaign number is inserted on the label. This will indicate that the campaign has been completed.
1. Reinstall the Fuel and Oil Fittings to the pump and CAP ALL CONNECTIONS.
2. Reinstall throttle return springs and tubes, (if removed).
3. Secure pump with (4) hex nuts, (refer to FIGURE 12, ITEM A)
4. Affix return labels over existing labels on top of lid, and front side of container, (refer to FIGURE 12, ITEM B).
5. Contact the shipper to arrange for return shipment.
6. Place all documents in envelope and return with pump. (Include a legible copy of repair order with TAC case number noted on repair order.)
Dear General Motors Customer
General Motors of Canada Limited has determined that certain 1992 GMC Forward W5-W7 Series may experience erosion in the fuel injection pump housing. Analysis has shown erosion to be the result of cavitation in the fuel injection pump housing. Erosion could eventually allow diesel fuel to leak into the engine crankcase causing oil dilution.
o Increased crankcase oil levels
o Decrease in fuel economy
o Poor acceleration
To correct this condition, your dealer will replace the fuel injection pump and fuel return pipe. In addition, if the vehicle did not have a fuel pipe modification completed from Product Campaign Bulletin 2N20, dated November 1992, the modification will also need to be completed at this time and is included in the labour time allowance of this bulletin. Dealers are also required to complete an oil and oil filter (vehicle is equipped with two oil filters) change free of charge to the customer. This oil and filter charge is only valid at time of fuel injection pump replacement under this product campaign and is also included in the labour time allowance of this bulletin.
This service will be provided for you at no charge.
Please contact your GM dealer as soon as possible to arrange a service date.
If parts are required, ask your dealer for details regarding their availability. If parts are not in stock, they can be ordered before scheduling your service date.
This letter identifies your vehicle. Presentation of this letter to your dealer will assist their Service personnel in completing the necessary correction to your vehicle in the shortest possible time.
We are sorry to cause you this inconvenience; however, we have taken this action in the interest of your continued satisfaction with our products.
Customer Support Department General Motors of Canada Limited
General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.