Jeep Wagoneer/Commando/Cherokee 1984-1998

Injection Pump

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Removal & Installation



See Figures 1, 2, 3 and 4

Special tools are needed for this procedure.

  1. Disconnect the negative battery cable.
  2.  
  3. Using heavy clamps, clamp off the coolant inlet and outlet hoses at the cold start capsule. Then, disconnect them.
  4.  
  5. Disconnect the throttle cable and fuel shut-off solenoid wire.
  6.  
  7. If so equipped, disconnect the automatic transmission throttle cable, and cruise control cable.
  8.  



Click image to see an enlarged view

Fig. Fig. 1: Diesel timing belt cover



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Fig. Fig. 2: Injection pump adjustment points. (3) is the control cable screw; (4) is the injection pump shaft locknut; (A) is the fuel outlet fitting

  1. Disconnect and plug the fuel delivery and return hoses.
  2.  
  3. Remove the alternator drive belt.
  4.  
  5. Remove the power steering drive belt.
  6.  
  7. Remove the timing belt cover.
  8.  
  9. Rotate the crankshaft clockwise, as viewed from the front, until No.1 piston is at TDC compression. Make sure that the camshaft sprocket timing mark is aligned with the center boss on the cylinder head cover. Make sure, also, that the injection pump sprocket timing mark is aligned with the center of the boss on the injection pump.
  10.  
  11. Rotate the crankshaft counterclockwise, moving the sprocket timing marks by 3 timing belt teeth.
  12.  
  13. Install sprocket holding tool MOT-854 or its equivalent. It may be necessary to turn the sprocket back and forth slightly to install the tool.
  14.  
  15. Loosen the sprocket retaining nut on the end of the injection pump shaft, and turn it out just to the end of the threads.
  16.  
  17. Assemble the sprocket removal tool jaws, B.Vi.48 and the short screw B.Vi.859, on the sprocket removal tool, B.Vi.2801 or there equivalents.
  18.  
  19. Attach the tool to the injection pump sprocket.
  20.  
  21. Disconnect all the fuel pipe fittings from the injectors. Plug the injectors to prevent dirt from entering the fuel system.
  22.  
  23. Disconnect the fuel pipe fittings from the fuel injection pump. Plug the fittings to prevent dirt from entering the system.
  24.  
  25. Remove the fuel line fittings from the vehicle. Remove all hoses and connectors from the injection pump assembly.
  26.  
  27. Remove the injection pump rear bracket retaining nuts.
  28.  
  29. Remove the plastic shield from under the injection pump.
  30.  
  31. Remove the three retaining nuts located at the front of the injection pump. The lower nut is hard to get at. It may be necessary to remove the alternator to get a wrench on it.
  32.  
  33. Using the sprocket removal tool, separate the injection pump from the sprocket.
  34.  
  35. Remove the removal tool and the sprocket nut. The sprocket holding tool and the timing belt will hold the sprocket in plate. facilitating injection pump installation.
  36.  
  37. Remove the injection pump from the mounting brackets.
  38.  
  39. Remove the key from the shaft.
  40.  
  41. Remove the screw plug and copper washer located between the four high pressure fuel outlets, at the rear of the pump. Install dial indicator support tool Mot.856 or its equivalent in its place.
  42.  



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Fig. Fig. 3: Injection pump sprocket removal tools



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Fig. Fig. 4: Sprocket holding tool. (D) is the camshaft sprocket bolt

To install:
  1. Install the stem of dial indicator Mot.LM in the support tool.
  2.  
  3. Position a locknut and nut on the end of the injection pump driveshaft.
  4.  
  5. Tighten the locknut against the nut.
  6.  
  7. Loosen the control cable set screw on the clevis, move the levers back slightly and turn the clevis pin 1 / 4 turn to disengage the cold start system.
  8.  
  9. Using the locknut, turn the pump driveshaft in the normal direction of rotation, to position the piston at bottom dead center. The dial indicator pointer will stop moving when the piston is at BDC. Zero the pointer.
  10.  
  11. The pump driveshaft keyway should be located just before the centerline of the number 1 fuel outlet fitting.
  12.  
  13. Remove the nut and locknut.
  14.  
  15. Insert the key in its keyway.
  16.  
  17. Mount the injection pump in the sprocket, aligning the key.
  18.  
  19. Loosely install the washers and retaining nuts on the mounting bracket studs.
  20.  
  21. Install the sprocket washer and retaining nut on the pump driveshaft. Tighten the nut to 37 ft. lbs. (50 Nm).
  22.  
  23. Remove the sprocket holding tool.
  24.  
  25. Rotate the crankshaft in a clockwise direction at least 2 full revolutions. Check the timing belt tension as follows:
    1. Loosen the timing belt tensioner bolts 1 / 2 turn each, maximum.
    2.  
    3. The belt tensioner should, automatically, place the proper tension on the belt.
    4.  
    5. Using belt tension gauge Ele.346-04 or its equivalent, at the straight, upper run, between the pump and camshaft sprockets, check belt deflection. Deflection should be 3-5mm when the gauge shoulder is flush with the plunger body.
    6.  

  26.  
  27. Remove the threaded plug from the block, just behind the pump, and insert TDC Rod Mot.861 or its equivalent.
  28.  
  29. Slowly rotate the crankshaft clockwise until tool Mot.861 or its equivalent, can be inserted into the TDC slot in the crankshaft counterweight.
  30.  
  31. At this point, the dial indicator pointer should indicate a piston travel distance of 0.80-0.84mm.
  32.  
  33. If the indicated travel is not within specifications, adjust it as follows:
    1. Rotate the pump toward, then away from the engine to increase travel.
    2.  
    3. Rotate the pump away from the engine to decrease travel
    4.  

  34.  

Adjustment should always be made by rotation away from the engine. That's why rotation toward the engine is necessary in Step 42a.

  1. Tighten the injection pump mounting nuts.
  2.  
  3. Remove the TDC Rod from the counterweight slot.
  4.  
  5. Observe the dial indicator and rotate the crankshaft clockwise 2 full revolutions until the rod can, once again, be installed into the counterweight hole. The dial indicator should return to 0, then move to 0.80-0.84mm. If so, injection pump static timing is correct.
  6.  
  7. Remove the TDC Rod and install the plug.
  8.  
  9. Remove the dial indicator and install the washer and screw plug in the pump.
  10.  
  11. Connect the high pressure lines at the injectors.
  12.  
  13. Compress the timing control lever and install the clevis pin in the first position on the cable clamp.
  14.  
  15. With the lever against the clevis, tighten the setscrew.
  16.  
  17. Install and tighten the pump rear support bracket nuts.
  18.  
  19. Install all other parts in reverse order of removal.
  20.  

Don't confuse the fuel delivery and return hose banjo bolts. The delivery banjo bolt has two 4mm diameter holes; the return banjo bolt has a calibrated orifice. Never use the banjo bolts from one pump on another!

STATIC TIMING ADJUSTMENT



See Figures 5 and 6

Special tools are needed for this job.

  1. Remove the injection pump as described above.
  2.  
  3. Remove the key from the shaft.
  4.  
  5. Remove the screw plug and copper washer located between the four high pressure fuel outlets, at the rear of the pump. Install dial indicator support tool Mot.856 or its equivalent in its place.
  6.  
  7. Install the stem of dial indicator Mot.LM or its equivalent in the support tool.
  8.  
  9. Position a locknut and nut on the end of the injection pump driveshaft.
  10.  
  11. Tighten the locknut against the nut.
  12.  
  13. Loosen the control cable setscrew on the clevis, move the levers back slightly and turn the clevis pin 1 / 4 turn to disengage the cold start system.
  14.  
  15. Using the locknut, turn the pump driveshaft in the normal direction of rotation, to position the piston at bottom dead center. The dial indicator pointer will stop moving when the piston is at BDC. Zero the pointer.
  16.  
  17. The pump driveshaft keyway should be located just before the centerline of the number 1 fuel outlet fitting.
  18.  



Click image to see an enlarged view

Fig. Fig. 5: Installing the dial indicator and support tool



Click image to see an enlarged view

Fig. Fig. 6: Injection timing procedure using a dial indicator

  1. Remove the nut and locknut.
  2.  
  3. Insert the key in its keyway.
  4.  
  5. Mount the injection pump in the sprocket, aligning the key.
  6.  
  7. Loosely install the washers and retaining nuts on the mounting bracket studs.
  8.  
  9. Install the sprocket washer and retaining nut on the pump driveshaft. Tighten the nut to 37 ft. lbs. (50 Nm).
  10.  
  11. Remove the sprocket holding tool.
  12.  
  13. Rotate the crankshaft in a clockwise direction at least 2 full revolutions. Check the timing belt tension as follows:
    1. Loosen the timing belt tensioner bolts 1 / 2 turn each, maximum.
    2.  
    3. The belt tensioner should, automatically, place the proper tension on the belt.
    4.  
    5. Using belt tension gauge Ele.346-04 or its equivalent, at the straight, upper run, between the pump and camshaft sprockets, check belt deflection. Deflection should be 3-5mm when the gauge shoulder is flush with the plunger body.
    6.  

  14.  
  15. Remove the threaded plug from the block, just behind the pump, and insert TDC Rod Mot.861 or its equivalent.
  16.  
  17. Slowly rotate the crankshaft clockwise until tool Mot.861 or its equivalent can be inserted into the TDC slot in the crankshaft counterweight.
  18.  
  19. At this point, the dial indicator pointer should indicate a piston travel distance of 0.80-0.84mm.
  20.  
  21. If the indicated travel is not within specifications, adjust it as follows:
    1. Rotate the pump toward, then away from the engine to increase travel.
    2.  
    3. Rotate the pump away from the engine to decrease lift.
    4.  

  22.  

Adjustment should always be made by rotation away from the engine. That's why rotation toward the engine is necessary in Step 20a.

  1. Tighten the injection pump mounting nuts.
  2.  
  3. Remove the TDC Rod from the counterweight slot.
  4.  
  5. Observe the dial indicator and rotate the crankshaft clockwise 2 full revolutions until the rod can, once again, be installed into the counterweight hole. The dial indicator should return to 0, then move to 0.80-0.84mm. If so, injection pump static timing is correct.
  6.  
  7. Remove the TDC Rod and install the plug.
  8.  
  9. Remove the dial indicator and install the washer and screw plug in the pump.
  10.  
  11. Connect the high pressure lines at the injectors.
  12.  
  13. Compress the timing control lever and install the clevis pin in the first position on the cable clamp.
  14.  
  15. With the lever against the clevis, tighten the setscrew.
  16.  
  17. Install and tighten the pump rear support bracket nuts.
  18.  
  19. Install all other parts in reverse order of removal.
  20.  

Don't confuse the fuel delivery and return hose banjo bolts. The delivery banjo bolt has two 4mm diameter holes; the return banjo bolt has a calibrated orifice. Never use the banjo bolts from one pump on another!

 
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