Checking and repairing fuel injectors Fig. 7 Dip nozzle body and nozzle needle separately into filtered Diesel fuel and check their gliding quality. When pulled out of the nozzle body by up to a third of its length the nozzle needle must sink back to its seat under its own weight when released. Place injection nozzle on top, ensuring that the associated pins are correctly fitted. 7 Fig. 8 Screw on union nut, tightening it to the specified torque (see “Service Data”). Check injector on the manual test stand. 8 Ensure that the edge-type filter is correctly seated in the injector body. Fig.
9 A dislocated sieve bar filter throttles and prolongs the injection and consequently causes poor perfor- mance, high consumption and heavy smoke formation in conjunction with heavy engine vibra- tions. For this reason measure the rim offset of the sieve bar filter in the nozzle inlet. 9 1 The sieve bar filter must not be pressed into the nozzle holder farther than approx 5 mm. In the event of larger rim offsets, the nozzle holder is to be replaced. 35