1 phenomena
Diesel engine is not easy to start, or start speed is not easy to improve.
2 reason analysis
Fuel combustion in the engine cylinder gas expansion work force generated by the engine, in addition to overcome each part of friction resistance and driving the auxiliary device (such as the Baotou beiben heavy truck parts water pump, fuel pump, fan, air compressor, generator, pump etc.), finally through the flywheel output power. If the engine cylinder heat generated or small thermal utilization efficiency is not high, the friction resistance is too large or the driving auxiliary device of power consumption will increase, the engine output power is reduced, the engine to. The reasons for the above phenomenon are:
(L) effect of fuel supply system failure
Insufficient oil supply
Fuel system should be timely and appropriate to the cylinder spray good fuel atomization. If the fuel system is faulty, the amount of oil in the cylinder is less, and the heat generated by the combustion is reduced. When the heat is reduced to not meet the engine load, the engine is weak.
Spraying quality is too poor
Baotou beiben heavy truck parts work engine injector spray quality is poor, the fuel oil spraying in a cylinder surface area, combined with oxygen reduction, even if the cylinder oil injection of many people, but because of the poor quality of atomization, and the oxidation reaction, the heat generated is less.
Influence of fuel injection advance angle
The amount of fuel in the cylinder should be suitable. If the fuel pressure increase rate in the rapid tender period, easy to cause engine work rough. Rough work will consume some of the power that is not efficient use of thermal efficiency, the external output effective power reduction. Fuel injection advance angle is too small, the combustion process most moved to the expansion work, so that the pressure rise rate decreased, the maximum pressure drop, the exhaust temperature increases, the heat loss of the cooling water, the thermal efficiency decreased significantly.
The effect of aeration rate.
Can the fuel combustion in the cylinder, mainly carbon atoms with oxygen in the diesel oil chemical reaction (carbon dioxide) heat released results, if the air filter is clogged the section air circulation (reduced engine turbocharger equipped with turbocharger intake to reduce the amount of the miasma) or the timing effect due to insufficient engine charge, resulting in carbon atom and oxygen atom in the fuel can not fully reflect the heat, so reduce the engine to.
Mechanical tolerance of working medium and bad seal
Such as cylinder gasket damage, valve closed lax, piston and cylinder wall with the gap is too large, can cause leakage and compression bad, resulting in fuel combustion effect in the cylinder is not good, the engine is weak.
The influence of environmental temperature
When the ambient temperature is too high, often cause engine overheating. Under the double effect of high environmental temperature and engine overheating, the air expands, thus affecting the inflation of the engine and decreasing the engine power. Environmental temperature is too low, it will cause fuel in the cylinder evaporation bad, resulting in combustion is not complete, that is, the cylinder working medium to reduce the heat generated.
(2) the influence of engine resistance
If Baotou beiben heavy truck engine assembly, oil tight fitting too thick, will cause the engine to high resistance. The engine produces the power besides overcomes itself friction and the auxiliary device resistance, then the output effective power reduces, namely engine weakness.

3, diagnosis and elimination
According to the analysis of the causes and fault phenomena diagnosis.
(1) if the engine starts to exhaust less and is not easy to start, the reason is that the fuel supply system is insufficient, the fuel system should be based on the fault diagnosis and exclusion.
(2) if the engine starts smoothly, but the exhaust black smoke, while the engine speed is not easy to improve, the main reason is that the air entering the cylinder is too small, should check the intake air filter part (a turbocharger engine also check the turbocharger, and excluded).
(3) if the engine overheating occurs, most of which is due to the injection time is too late, is the engine failure reason, should be adjusted. Its adjustment method see the engine can not start the narrative section.
(4) if the engine exhaust pipe has blue and white smoke, indicating that the engine is weak due to air channeling caused by cylinder, should be processed.
(5) check the air leakage
Move the engine flywheel to check cylinder piston compression top dead point, remove the injector, low gears and pull stop brake, and then use the hose from the nozzle hole to the combustion chamber filled with compressed air, then the other one in the intake pipe and exhaust pipe, oil filler, cylinder pad or radiator outlet listen, observe the leak sound. If heard somewhere leak sound, indicating that the cylinder seal is bad. For example, in the exhaust pipe and intake pipe leak sound heard, the gas is not tightly closed, or in the radiator water inlet leak sound heard, that gasket is damaged. After the identification should be excluded.
(6) check engine resistance
Move the engine flywheel with a crowbar, if the feeling is the same type of diesel or other than the normal use of labor, the diesel engine high resistance. If the diesel engine was repaired, mostly due to tight assembly caused by, should run or re assembly.
(7) check the gas distribution phase
If the checks are normal, then the diesel engine to reason in gas phase, and should check valve clearance valve and inlet and exhaust valve to open or close the crank angle, and then the control can be identified with a bitmap.
Valve phase inspection method: valve clearance adjustment should conform to the technical documents specified value. Open the window on the engine flywheel housing cover, and the rotation of the flywheel to make the first move with a crowbar cylinder piston compression top dead point, a 3 fat dial and pointer and dial fixed on the pulley, the pointer is fixed on the front cover, the pointer dial “J”. Remove the valve cover, and a dial gauge bracket is arranged on the cylinder head detection began leveraging the rotation of the flywheel rotating rod valve mechanism by hand, when the push rod can not rotate, said valve will open, then the pointer on a dial indicator, the valve opening angle; the hands touch rod and rocker arm (push rod end) will be adjusted to zero offset table, and then continue to rotate the crankshaft, when the dial pointer back to zero, and then turn the push rod by hand, won’t turn to turn on the sector, for the valve closed, then indication pointer on a dial to close the angle valve.
From the valve open to close, the angle of the crankshaft is the valve opening sustained angle. The examination results with the technical regulations of the machine with gas phase diagram comparison, if the ultra big difference, should be and to find out the ultra poor reasons, such as gear wear, correct installation position of the drive gear, and the cam shaft keyway and key damage, working surface of the cam wear is identified, should be excluded. General diesel engine only check the first cylinder can be, other cylinders of the gas phase by the camshaft to ensure.