Fuel Injection Pump - FAW Jiefang Automotive 485 Operation & Maintenance Manual

(2) When the needle-valve couple is jammed or atomization is poor, it is necessary to clean it.
The jammed needle-valve couple should at first be immersed in kerosene for some time, then the
needle-valve should be clamped by a pair of wire pliers lined with cloth, and turned gently and
pulled out. Care should be given to prevent it from being napped. Wooden pieces with gasoline or
kerosene can be used to scrub the needle-valve couple, and metal pieces are prohibited for this
purpose. If the needle-valve and valve body are not smooth or active enough, it is possible to
adjust it by grinding it with clean kerosene. When pair-grinding them, the needle-valve should not
collide with the valve body seat surface. After the grinding, carefully clean them, with no dirt
leftover.
3. Protruding distance
The distance between injector head end and the bottom plane of cylinder cover should be 3
± 0.25 mm. Adjustment, if necessary, can be made with 0.2 mm copper shim.
The fuel injection pump has been adjusted and inspected before delivery. Re-adjustment, if
necessary, should be made on a test stand specially for fuel injection pump, with standard fuel
injector and standard-length high-pressure fuel pipes on it. For specific parameters for adjustment,
please refer to relevant instructions for fuel injection pump.
IV. Fuel injection pump