Volvo Coupes/Sedans/Wagons 1970-1989 Repair Guide

Fuel Pump/Injection Pump

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The fuel pump is also the injection pump and is located on the left rear side of the engine, driven by a belt running off the rear of the camshaft. The pump supplies the engine with more fuel than it can use, the excess fuel being returned to the fuel tank through suction/return lines. The system constantly bleeds itself of air. Because the pump moves such large amounts of fuel, it tends to stay cool and this reduces the chances of vapor lock. The pump is lubricated by the fuel passing through it. Do not use fuel additives unless specifically recommended by Volvo for fear of damaging the pump.

The pump contains a single piston which rotates and distributes fuel to each injector in the correct sequence, much in the same way the distributor on a gasoline engine distributes the spark to the spark plugs.

REMOVAL & INSTALLATION



See Figure 1


WARNING
The use of the correct special tools or their equivalent is REQUIRED for this procedure. Several special tools are needed to remove and install the pump and to set its timing. If these tools are not available, do not attempt to remove the pump. The Volvo tool numbers are given in the procedure.

  1. Pinch off and remove the two coolant hoses running to the cold start device on the fuel pump.
  2.  
  3. Disconnect the accelerator linkage at the pump and disconnect the wire from the stop valve on the top of the pump. Disconnect the hose coming from the intake manifold.
  4.  
  5. Remove the rear timing belt cover and thoroughly clean the fuel lines and their connections at the injection pump.
  6.  
  7. Disconnect the fuel lines at the pump and plug the open connections to prevent dirt from entering the fuel system.
  8.  
  9. Remove the vacuum pump and its plunger.
  10.  
  11. Clean and remove the delivery lines at the fuel injectors. Plug all connections. Remove the lines as a unit and set them aside.
  12.  
  13. Set cylinder No. 1 to TDC injection stroke. At this position, the 0 mark on the flywheel aligns with the pointer and the notch on the injection pump pulley aligns with the notch on the pump housing. Both valves on No. 1 cylinder are closed and their camshaft lobes are pointing up at equally large angles.
  14.  



Click image to see an enlarged view

Fig. Fig. 1: Set the No. 1 cylinder to TDC for the injection stroke-the cam lobes are visible through the oil filler cap and will appear as shown

  1. Loosen the retaining bolts for the injection pump, push the pump up, and remove the pump drive belt. Tighten one bolt to hold the pump in the upper position.
  2.  
  3. Loosen the center bolt in the rear camshaft gear while using wrench 5199 to hold the gear. The bolts will be easily accessible if wrench 5201 is used.
  4.  

The camshaft must not rotate. Loosen the bolt only enough to rotate the gear on the camshaft.

  1. Insert locking pin (No. 5193) into the injection pump gear to lock it in position. Remove the injection pump gear nut and washer.
  2.  
  3. With the pin still in position, use a puller to remove the pump gear.
  4.  
  5. Remove the bolts retaining the front injection pump bracket to the engine, then remove the bolts retaining the pump and remove the pump from the engine.
  6.  
  7. Install the pump on the engine and tighten the bolts only finger tight so that pump position can be adjusted.
  8.  
  9. Set the injection pump so that the mark on pump and the pump bracket align, then tighten the retaining bolts.
  10.  
  11. Make sure the shaft key is correctly installed and install the injection pump gear, washer and nut. Use pin 5193 to hold the gear while tightening the nut.
  12.  
  13. Proceed to Setting the Injection Pump Timing, below.
  14.  
  15. After the injection pump timing is set, fill the pump with clean diesel fuel through the fuel line connection. Make sure you filter the fuel before pouring it into the pump.
  16.  
  17. Install the rear timing gear cover. Connect the fuel lines and fuel delivery pipes. Tighten the fuel line cap nuts and the fuel line banjo bolts to 18 ft. lbs. (24 Nm).When installing the fuel lines on the pump, do not mix the banjo bolts: the bolt for the fuel return line has a small hole in it and is marked OUT.
  18.  
  19. Install the vacuum pump and all remaining components. Adjust the accelerator linkage.
  20.  

SETTING INJECTION PUMP TIMING



See Figures 2, 3, 4 and 5


WARNING
The use of the correct special tools or their equivalent is REQUIRED for this procedure.

  1. Set cylinder No. 1 to TDC injection stroke. At this position, the 0 mark on the flywheel aligns with the pointer and the notch on the injection pump pulley aligns with the notch on the pump housing. Both valves on No. 1 cylinder are closed and their camshaft lobes are pointing up at equally large angles.
  2.  
  3. Disconnect the cold start device on the injection pump by loosening screw No. 1 in the illustration, pushing the lever forward and rotating the sleeve 90°. Push the lever back against the stop. Do not touch screw No. 2 in the illustration or the cold start device will have to be reset on a test bench.
  4.  



Click image to see an enlarged view

Fig. Fig. 2: Loosen screw No. 1 to disconnect the cold start device, but do not loosen screw No. 2

  1. Loosen the injection pump retaining screws and turn the pump so that the markings on the injection pump and the pump bracket align. Install the lock pin (No. 5193) in the injection pump gear to lock the gear in position. Any pin can be used to lock the gear, however there cannot be any movement of the gear when the pin is installed.
  2.  



Click image to see an enlarged view

Fig. Fig. 3: Loosen the injection pump retaining screws and turn the pump so the markings align

  1. Remove the plug in the injection pump distributor and install special holder 5194 and a dial indicator gauge with a measuring range of 0-0.12 in. (0-3mm.) Set the dial gauge at approximately 0.08 in. (2mm).
  2.  
  3. Remove the stop pin and turn the injection pump (using its gear) in its normal direction of rotation until the marks on the injection pump gear and the bracket align.
  4.  



Click image to see an enlarged view

Fig. Fig. 4: With the dial gauge properly installed, turn the pump and align the marks

  1. Turn the injection pump gear slightly counterclockwise until the dial gauge indicates its lowest reading. In this position set the dial gauge to zero. Turn the injection pump gear clockwise until the marks on the gear and the bracket align again, then refit the lock pin to lock the gear in position.
  2.  



Click image to see an enlarged view

Fig. Fig. 5: Relationship between the pump motion and dial indicator reading when setting the diesel injection pump timing

  1. Install the rear camshaft gear (if removed) and tighten its center bolt only hand tight. Install the drive belt.
  2.  
  3. Adjust the drive belt to the proper tension by moving the pump on its mounts. If you're using the Volvo tension gauge (5197), set the tension gauge to 12.5 and apply tension to the belt until the mark on the plunger of the gauge is flush with the gauge sleeve. Depress the belt heavily with your hand then recheck and adjust the tension.
  4.  


WARNING
The dial indicator readings given in the text below are for 1979-1981 US and Canada D24 engines. Specifications for other engines are given at the end of the section.

  1. Use wrench 5199 (or a suitable substitute) to hold the rear camshaft gear in place and install wrench 5201 with a torque wrench attached on the center bolt. The torque wrench should be installed at a 90° angle to wrench 5201 to give correct readings. Use wrench 5199 or its substitute to turn the camshaft gear until the dial gauge in the injection pump reads 0.028 in. (0.70mm). Hold the gear in this position and tighten the center bolt to 73 ft. lbs. (99 Nm) without moving either the camshaft or the gear.
  2.  
  3. Remove the lock pin and turn the engine over two full turns (one complete four stroke cycle) until the No. 1 cylinder is again on TDC compression stroke. Check the reading on the dial indicator gauge. It should read 0.028 in (0.70mm). If the reading is correct, proceed to Step 13.
  4.  
  5. If the reading is less than 0.028 in. (0.70mm), loosen the injection pump retaining screws and turn the pump inward until a reading of 0.028 in. (0.70mm) is obtained. Repeat Step 10.
  6.  
  7. If the reading is more than 0.028 in. (0.70mm), loosen the injection pump retaining screws and turn the pump outward until the reading on the gauge is approximately 0.024 in. (0.60mm). Next, turn the pump inward to obtain a reading of 0.028 in (0.70mm) and tighten the retaining bolts. Repeat Step 10.
  8.  

When adjusting, do not tap or knock the pump as this will alter the settings.

  1. Remove the dial indicator and its holder and install the plug. Tighten the plug to 6.5 ft. lbs. (9 Nm).
  2.  
  3. Attach the cold start device. Reverse Step 1, above. Install all remaining components.
  4.  

The following are injection pump timing specifications in millimeters of dial indicator reading:



D20: 0.80
 
D24: 0.85
 
1982-83 D24T: 0.80
 
1984-85 D24T: 0.85, Exc. Calif.
 
1984-85 D24T: 0.75 Calif.
 

 
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