BMW Coupes and Sedans 1970-1988 Repair Guide

Injection Pump



This is a complex operation requiring several special tools. Use 13 5 020 or equivalent to remove injection lines. Use 13 5 010 and 13 5 061 or equivalent to press the injection pump off its sprocket. Also required are 2 M6-20mm bolts and plastic caps to seal the openings.

  1. Remove the drain plugs from both the block and the radiator to completely drain coolant. Remove the fan cowl and fan as described earlier in this section.

When draining coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze, and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.

  1. Remove the oil filler cap to watch the valves. Turn the crankshaft with a socket wrench so the No. 1 cylinder is at TDC firing position (No. 6 valves overlapping).
  3. Disconnect and remove the upper and lower radiator hoses. Remove the alternator drive belt. Remove the timing belt cover, as described earlier in this section.
  5. Using a backup wrench, use the special injection line wrench to disconnect the inlet line at the injection pump. Plug the opening.
  7. Disconnect the fuel return line at the connector below the pump. Remove the wiring harness clamp nearby.
  9. Remove the clamp for the oil dipstick tube. Disconnect the hoses on the timing advance unit. Remove the air collector bracket near the rear of the injection pump. Remove the pop-off valve air connection.
  11. Disconnect the hoses for boost pressure, injection pump oil drain, vacuum, and the altitude compensator.
  13. Remove the line running from the turbo to the intake manifold. Remove the oil trap from the valve cover. Then pull off the 3 plugs nearby.
  15. Disconnect the fuel shutoff and idle switch connectors.
  17. Disconnect the throttle cables at the cam and remove the cable housings from the bracket.
  19. Disconnect all the coupling nuts at the injection nozzles with the special wrench, being careful not to bend the injection lines. Do the same with the lines at the injection pump end. Plug all openings and then pull the lines out of the way.
  21. Remove the nut attaching the injection pump sprocket to the pump. Then, bolt the special tools for pressing the pump off the sprocket to the sprocket. Turn the crankshaft as necessary to line the bolt holes up so the bolts fastening the tool to the block on either side can be installed and then install them.
  23. Remove the 2 nuts situated directly behind the front cover. Then, remove the 3 bolts that fasten the pump at the rear.
  25. Turn the large bolt at the center of the special tool and press the pump out of the sprocket.
  27. Pull off the EGR pressure converter hoses at the converter. Remove the wiring harness for the pump out of the clips. Remove the pump. Be careful not to disturb the pump shaft. The key must remain at the top (don't lose it).

To install:
  1. Install the pump so the key fits through the slot in the sprocket. Then, install and tighten the 2 nuts situated directly behind the front cover. Make sure the pump rests tightly against its mounting on the front cover.
  3. Remove the special tool used to press the pump out of the sprocket. Then, install the sprocket bolt and torque it to 33-35 ft. lbs. (43-45 Nm).
  5. Adjust the static timing as described in this section.
  7. Perform the remaining procedures in reverse order. Install the injection lines as described above under Injector Nozzle Replacement. Bleed the fuel system as described in this section.


See Figure 1

To perform this procedure, a special dial indicator gauge and a timing pin, BMW tools 13 5 330 and 11 2 300 or equivalent are needed.

  1. Make sure the coolant temperature is above 68°F (20°C) so the throttle lever will rest against the idle stop.
  3. Unfasten the coolant overflow tank and move it out of the way. Disconnect and plug the overflow hose.
  5. Remove the plug in the injection pump head (between 2 of the lines going to the injectors). Install 13 5 330 or equivalent and hand tighten it. Remove the fan as described in the cooling system section. Turn the crankshaft, watching the dial gauge, in the forward direction until the gauge reaches its maximum value. Then, zero the gauge. Continue turning the engine toward TDC while pressing the timing pin into the timing hole in the flywheel housing. The pin will lock into a hole in the flywheel, keeping the engine at TDC. Check that No. 6 valves are overlapping by removing the oil filler cap. Repeat the procedure, to set the engine at TDC firing position for No. 1, if the valves of No. 6 are not overlapping. Make sure to zero the gauge in the same way.
  7. The reading should be 0.02-0.03 inches (0.65-0.67mm). If it is within these limits, remove the gauges and replace the plug with a new gasket, restoring other parts to their normal condition. If the reading is incorrect, follow the rest of the steps.
  9. Remove the bracket for the air collector that is near the injection pump. Remove the wiring harness from its clamps.
  11. Remove the bolts 3 , 4 and 5 at the rear of the pump.

Click image to see an enlarged view

Fig. Fig. 1: Loosen bolts (3), (4) and (5) before adjusting the pump

  1. Loosen the hose clamp that's in the way at the front of the pump. Loosen the 2 nuts behind the front cover just enough to permit turning the pump. To increase the reading or advance the timing, turn the pump toward the engine. When the figure is within tolerance, tighten the 2 nuts on the front cover and then tighten 3-5 in numerical order at the rear. Reverse the remaining procedures.