Nissan Pick-ups and Pathfinder 1970-1988

Injection Pump Service

Print

REPLACING THE DELIVERY VALVE



See Figures 1, 2, 3, 4, 5 and 6

  1. Thoroughly clean the area around the nozzle tube and delivery valve.
  2.  
  3. Remove the nozzle tube.
  4.  
  5. Remove the delivery valve holder lock plate.
  6.  
  7. Remove the delivery valve holder and spring.
  8.  
  9. Using ST #57930-032, remove the delivery valve.
  10.  
  11. Position the delivery valve in the pump housing making sure no dirt gets between the top of the plunger barrel and the delivery valve.
  12.  
  13. Install a new delivery valve gasket. The gasket is installed with the larger face downward and may be tapped into place through the extractor.
  14.  
  15. Install the delivery valve spring.
  16.  
  17. Install the delivery valve holder and torque it to 22-25 ft. lbs.
  18.  
  19. Loosen the holder and retorque it.
  20.  
  21. Install the lock plate, nozzle tube and nozzle clamp.
  22.  



Click image to see an enlarged view

Fig. Fig. 1: Removing delivery valve holder lock plate



Click image to see an enlarged view

Fig. Fig. 2: Loosening the delivery valve holder



Click image to see an enlarged view

Fig. Fig. 3: Removing the delivery valve holder and spring



Click image to see an enlarged view

Fig. Fig. 4: Removing the delivery valve with special tool



Click image to see an enlarged view

Fig. Fig. 5: Plunger barrel removal, with delivery valves removed



Click image to see an enlarged view

Fig. Fig. 6: Inserting the plunger spring holder

REPLACING THE PLUNGER



  1. Remove the delivery valve.
  2.  
  3. Push the plunger spring up with two prybars and remove the lower spring seat from the plunger.
  4.  
  5. Insert a hooked wire through the top of the pump housing, down through the plunger opening and hook it on the lead unit of the plunger. Pull up to remove the plunger and barrel.
  6.  
  7. Immerse a new plunger in clean fuel oil and thoroughly wash off the rust preventive.
  8.  

The plunger was lapped at the factory. Do not hold it by the lapped section.

  1. Operate the plunger in clean fuel oil to check its operation.
  2.  
  3. Slowly insert the plunger and barrel into the pump with the barrel groove and plunger notch facing forward. Make certain the plunger piston pin is properly seated in the groove in the control sleeve.
  4.  
  5. Push the plunger spring up with two prybars and insert the lower spring seat.
  6.  
  7. Install the remaining parts in reverse of disassembly.
  8.  

CAMSHAFT REMOVAL & INSTALLATION



See Figures 7, 8, 9 and 10

  1. Remove the key from the camshaft and remove the four setscrews on the drive side of the pump housing. Remove the bearing cover.
  2.  
  3. Lay the pump on its side and remove the screw plugs from the bottom of the housing with tool #57910-112 or a ratchet handle.
  4.  
  5. Remove the set screws from the center bearing.
  6.  
  7. Remove the camshaft from the housing.
  8.  
  9. Install the bearing cover on the timer side of the housing.
  10.  
  11. Install the camshaft so that the alignment mark A is toward the timer.
  12.  
  13. Check the endplay. Endplay is 0-0.0012 in. (0-0.030mm).
  14.  



Click image to see an enlarged view

Fig. Fig. 7: Screw plug removal and installation



Click image to see an enlarged view

Fig. Fig. 8: Set Screw removal and installation



Click image to see an enlarged view

Fig. Fig. 9: Camshaft removal



Click image to see an enlarged view

Fig. Fig. 10: Measuring endplay

TAPPET REMOVAL & INSTALLATION



See Figures 11 and 12

  1. Remove the camshaft.
  2.  
  3. Install a tappet insert tool #57912-012 and remove the tappet holder, at the same time, removing the tappet from the holder. Be careful to avoid damaging the housing plug hole threads.
  4.  
  5. Loosen the tappet insert tool, withdraw the tappet assembly into the camshaft chamber and remove the tappet from the housing with a tappet clamp.
  6.  
  7. Installation is the reverse of removal. Make sure that the mechanism works smoothly.
  8.  



Click image to see an enlarged view

Fig. Fig. 11: Inserting tappet holder and insert tool



Click image to see an enlarged view

Fig. Fig. 12: Removing tappet with tappet clamp

PLUNGER REMOVAL & INSTALLATION



See Figures 13, 14, 15 and 16

  1. Remove the tappets.
  2.  
  3. Remove the plungers using plunger tool #57921-412 or equivalent, together with the lower spring seat.
  4.  
  5. Place any reusable plungers in the corresponding plunger barrels and immerse them in kerosene or safe solvent.
  6.  
  7. Remove the plunger springs, upper spring seats and control sleeves.
  8.  
  9. Lay the housing on it side and position the control rack so that the punch marks on both sides are the same distance from each end of the housing.
  10.  
  11. Install the control sleeve with the gap in the sleeve facing straight upward. At the same time install the spring seats.
  12.  
  13. Install the plunger spring in the housing.
  14.  
  15. Install the plunger in the barrel using tool #57921-412, along with the lower spring seat.
  16.  
  17. Make sure the mechanism functions smoothly.
  18.  



Click image to see an enlarged view

Fig. Fig. 13: Removing plungers with special tool



Click image to see an enlarged view

Fig. Fig. 14: Removing plungers springs, control sleeves and upper spring seats



Click image to see an enlarged view

Fig. Fig. 15: Control rack; punch mark is indicated by arrow



Click image to see an enlarged view

Fig. Fig. 16: Control sleeves installed

TESTING AND ADJUSTING THE FUEL INJECTION PUMP



See Figures 17, 18, 19 and 20

It is necessary to inspect and adjust the pump, using a pump tester, whenever it has been disassembled and assembled, when the plunger or plunger barrel have been replaced or when any of the component parts have been replaced. Use nozzle tube #57805-002 and test nozzle #5000-101, starting pressure 1422.3 psi. Clean No. 2 fuel should be used. Rotating direction, from drive side, is clockwise. Sequence is 1-4-3-2

Starting Timing
  1. Remove the fuel feed pump and cover plate from the injection pump.
  2.  
  3. Install the injection pump on the tester and holding fixture.
  4.  
  5. Connect the test coupling to the tester driveshaft with the coupling disc.
  6.  
  7. Remove the cap and position the tester dial to measure the camshaft rotating angle.
  8.  
  9. Install a tappet lift gauge on the No.1 tappet.
  10.  
  11. Bottom the tappet and set the dial gauge to zero.
  12.  
  13. Bleed the pump at the bleeder screw.
  14.  
  15. Loosen the nozzle holder ball valve.
  16.  
  17. Feed fuel to the pump inlet while slowly turning the pump tester by hand in the normal engine rotation direction. Fuel will flow from the test nozzle. When the fuel stops flowing, the injection point has been reached. The tappet, at this precise point, must be 0.08858-0.09251 in. (2.2249-2.3497mm) above BDC.
  18.  
  19. If the fuel does not stop flowing after 0.0926 in. (2.353mm), turn the adjusting bolt counterclockwise to raise the position of the plunger.
  20.  
  21. If the fuel stops flowing before 0.0886 in., turn the adjusting bolt clockwise to lower the plunger position.
  22.  
  23. When adjustment is made, tighten the locknut to 43-50 ft. lbs.
  24.  
  25. With the pump set at initial injection, set the angle scale mark on the tester flywheel at 0° or 180°.
  26.  
  27. If adjustment is correct, fuel should stop flowing at the No. 4 cylinder when the tester has been turned 60° in normal rotation. If fuel does not stop flowing at the correct time, adjust as above.
  28.  
  29. Check and adjust each cylinder in turn.
  30.  
  31. When timing for each cylinder is correct, position the cam at TDC, check the plunger piston pin-to-plunger barrel clearance and make sure that the tappet vertical clearance is at least 0.0118 in. (0.3mm) for each tappet.
  32.  



Click image to see an enlarged view

Fig. Fig. 17: Fuel feed pump removal



Click image to see an enlarged view

Fig. Fig. 18: Checking injection start timing with a lift gauge



Click image to see an enlarged view

Fig. Fig. 19: Turn the adjusting bolt



Click image to see an enlarged view

Fig. Fig. 20: Checking tappet clearance

Standard Fuel Injection Volume Adjustment

See Figures 21, 22, 23 and 24

  1. Determine the zero position of the control by attaching the measuring device to the pump and pushing the index all the way to governor side. Match the scale on the left end of the index and set the 0 (zero) position of the scale at the position at which the measuring device index stops. On RSV mechanical governors, loosen the stop bolt to align this index.
  2.  
  3. Remove the rack guide screw from the rear of the pump housing and supply the lock screw attached to the tester. Secure the control rack in the standard position for adjustment.
  4.  

The lock screw should be tightened by hand; overtightening will bend the rack.

  1. Start the tester and run the pump at rated speed.
  2.  
  3. Set the pump feed pressure at 21.3-22.75 psi and measure the injection volume at the rated stroke of the female cylinder.
  4.  
  5. In the same manner, measure the injection volume at rated speed and standard rack position. Compute the rate of unevenness of the injection.
  6.  
  7. If the results show that the injection volume and rate of unevenness are not within the limits, adjust by changing the relative position of the control pinion and control sleeve. This may be done by:
    1. Loosen the pinion set screw.
    2.  
    3. Place a pin in the hole in the control sleeve and adjust by moving the control sleeve along the control rack a little at a time.
    4.  
    5. When adjustment is completed, secure the pinion set screw.
    6.  
    7. Remove the lock screw from the control rack and reinstall the guide screw.

      Click image to see an enlarged view

      Fig. Fig. 21: Attaching a measuring device to the pump



      Click image to see an enlarged view

      Fig. Fig. 22: Installing the tester lock screw



      Click image to see an enlarged view

      Fig. Fig. 23: Loosening the pinion set screw



      Click image to see an enlarged view

      Fig. Fig. 24: Installing the appropriate sized pin

    8.  

  8.  

TESTING AND ADJUSTING THE GOVERNORRSV and RAD Mechanical Governor



See Figures 25 and 26



Click image to see an enlarged view

Fig. Fig. 25: Adjusting the full load stopper bolt (RAD shown)



Click image to see an enlarged view

Fig. Fig. 26: Adjusting the speed adjustment bolt (RSV shown)

  1. Match the adjusting device index to the zero point on the scale and set the control rack to the zero position.
  2.  
  3. Operate the control lever and make certain the full stroke of the rack is 0.827 in. (21mm).
  4.  
  5. Make certain that the rack moves freely in the direction for maximum fuel injection by the spring force of the starting spring.
  6.  
  7. Set the stop bolt to remove any significant load on the governor linkage.
  8.  
  9. Set the stop bolt to give a control rack setting of 0.0197-0.03937 in. (0.5-1.0mm).
  10.  

High Speed Adjustment

See Figure 27



Click image to see an enlarged view

Fig. Fig. 27: Adjustment chart

  1. Remove the governor rear cover.
  2.  
  3. Loosen the full load stop lock nut and adjust the full load stop so that its setting corresponds to an A rack position between K rotation and BC . See the accompanying chart.
  4.  

Unevenness = max. or min. injection volume for each plunger minus the main injection volume, divided by the mean injection volume, multiplied by 100.

  1. To increase the volume, turn the stop to the right; left to decrease.
  2.  

Maximum Speed Adjustment

See Figure 28



Click image to see an enlarged view

Fig. Fig. 28: Maximum speed stopper adjustment

Operate the pump at speed G and adjust the maximum speed stop so that the control rack position is G mm.

Speed Fluctuation Adjustment

Speed fluctuation can be controlled by varying the spring rate on RSV governors.

Balance Spring Adjustment
  1. Set the control lever to the point where it contacts the maximum speed stop and operate the pump at a rate of F , between A and B .
  2.  
  3. Install the balance spring assembly under the tension lever.
  4.  
  5. Tighten the balance spring assembly with tool #57916-212 until the control rack position G is H mm, and secure the lock nut.
  6.  
  7. Gradually accelerate the engine from speed D and make certain that the control rack is at G mm when the action of the spring ends at speed E .
  8.  

Idle Speed Adjustment

See Figures 29 and 30



Click image to see an enlarged view

Fig. Fig. 29: Adjusting the idling spring



Click image to see an enlarged view

Fig. Fig. 30: Auxiliary idle spring adjustment

  1. Set the control lever at the stop position so that the control rack is at point B .
  2.  
  3. Set the speed to D and tighten the idle auxiliary spring so that the position of the rack is C mm. Secure with the lock nut.
  4.  

Do not tighten the auxiliary idle spring too much or over-speeding will result.

Testing and Adjusting the Timer

See Figure 31

  1. Install a timing light, such as tool #5783-001 on the tester using the cover plate attaching bolts, so that the synchronizer lever attachment is applied to the tappet.
  2.  
  3. Start the pump and turn on the timing light.
  4.  
  5. Direct the light at the angle scale on the flywheel and measure the angular change based on variations in pump speed.
  6.  
  7. If the tester does not have an angle scale:
    1. Attach an angle scale to the timer coupling and mount a pointer on the tester driveshaft.
    2.  
    3. Operate the pump and direct the light on the scale.
    4.  

  8.  
  9. If the angular change is not within limits, disassembly the timer and adjust the spring force by increasing or decreasing the shim, or if necessary, replace the spring.
  10.  



Click image to see an enlarged view

Fig. Fig. 31: Pump installed on the tester - with synchronizer and strobe light

 
label.common.footer.alt.autozoneLogo