Fuel Injector: Adjustments

1. Invert injector and place into a suitable vise. Grip upper body along flats. Loosen the lower part of the injector, but do not remove.
2. Remove injector from vise, turn over, and lightly clamp the lower part of the injector in the vise and carefully remove upper body.
3. Visually inspect needle and nozzle assembly, ensure needle and nozzle are in satisfactory condition. Clean assembly in suitable solvent or replace needle/nozzle unit. Brass scrapers and brushes (used gently) can be used to remove hardened carbon deposits. Do not apply excessive pressure when removing carbon deposits or needle and/or nozzle damage will result. Replace any injector that shows signs of needle and seat damage or wear, oblong spray orifice, or discoloring of the nozzle.
4. Adjust opening pressure, if necessary. Using a suitable micrometer, check shim thickness and substitute shims. Each .05 mm (.0019 in.) shim thickness adjusts nozzle opening pressure by approximately 4.9 bar (71 psi).
5. Reassemble injector, torquing the halves to 51 ft. lbs. (70 Nm) and retest. Continue adjusting the shim thickness as needed until the proper opening pressure is obtained.