Analysis of forklift maintenance Black smoke from exhaust gas is that diesel fuel is not fully burned, and black smoke from exhaust gas not only reduces engine power, increases diesel consumption, but also tends to form carbon deposits and shorten engine service life. The reasons are as follows:
Analysis of forklift maintenance First:
1. Reasons for insufficient fresh air in cylinder:
(1) Excessive dust accumulation in the air filter element;
(2) The muffler is rusted, carbon or greasy.
(3) The clearance between the inlet and exhaust valves is too large, which reduces the valve opening;
(4) The parts of the adapter mechanism are loose, worn and deformed, the relative position of camshaft gear and crankshaft timing gear changes, and the valve opening and closing time is incorrect.
Analysis of Dongguan forklift maintenance Part 2:
2. Reasons for temperature and pressure drop at the end of cylinder compression:
(1) Excessive wear of cylinder barrel and piston ring, incorrect installation of piston ring or loss of elasticity cause air leakage of cylinder;
(2) The valve clearance is too small, which is easy to be jacked open when the vehicle is hot, or the valve is burnt and deposited, which causes the cylinder sealing is not tight;
(3) The joint surface between the cylinder head and the engine body, the injector and the cylinder head leaks;
(4) The valve sinks seriously, and the clearance between piston and piston pin, piston pin and connecting rod small end, connecting rod big end and connecting rod journal is too large, which increases the volume of combustion chamber and decreases the compression ratio.
3. Reasons for poor diesel atomization:
(1) The injector pressure is adjusted too low;
(2) The fuel injector pressure regulating spring is broken or jammed;
(3) The needle valve and valve seat of the fuel injector have carbon deposits, and the needle valve is stuck or excessively worn;
(4) The pressure reducing ring of the fuel delivery valve of the fuel injection pump is excessively worn, which causes the fuel injector to drip.
4. The reasons for incorrect fuel supply time and quantity are:
(1) The oil supply time is too late;
(2) At the beginning of starting, the gas pressure and temperature are low, and the fuel supply time is too early;
(3) Increase the fuel supply stroke after the plunger coupling of the fuel injection pump is worn;

(4) The stroke of the fuel injection pump regulating gear rod or pull rod is too large, resulting in too much fuel supply.