Diesel engine fuel system in addition to the early wear and tear of the three major precision, resulting in power drop, fuel consumption increased and exhaust smoke, the most prone to failure there are two categories: one is due to improper installation and installation of fuel injection pump caused by failure, The other is the use of the failure.

1, fuel pump installation caused by improper failure

(1) semi-circular key installation is not in place

In the case of a fuel injection pump with a flange connection, when the supply timing of the supply timing gear and the fuel supply advance angle automatic actuator and the fuel injection pump camshaft is incorrect, the supply timing is misaligned , The engine starts difficult, smoke and water temperature higher fault phenomenon. Such as through the flange on the arc can not be adjusted, the need to remove the fuel pump to re-install. After removal of the semi-circular keys can be observed on the obvious indentation.

(2) passive disk wrong 180 °

For pulsed pumps (such as 6105 and 6102 diesel engines) with cross couplings, it may be possible to install the passive disc in half a turn (180 °) during installation. Tube smoke-free phenomenon. Even if the engine in the strong start of the fire, there will be chaotic sound, exhaust pipe smoke and can not work. At this point should be disassembled screws, the fuel pump cam turn through half a circle to re-connect, and then through the curved hole fine-tuning to make oil timing.

(3) into the oil screw position is wrong

When the tubing is connected, if the oil return screw is misplaced on the fuel injection pump inlet, the fuel can not enter or only enter the fuel injection pump into the oil chamber due to the action of the check valve in the oil return screw so that the diesel engine can not start or After the start can not increase the speed of fuel. At this point hand pump pump oil resistance is great, or even unable to press the hand pump. At this time as long as the inlet and outlet screws to replace the location of the replacement can be troubleshooting.

2, often used in the failure

(1) low-pressure oil supply poor

Diesel engine from the Baotou North Ben heavy truck accessory fuel tank to the fuel injection pump into the oil chamber between the inlet and outlet pipeline are low-pressure oil, when the pipe joints, gaskets and tubing due to damage and oil leakage, will make air into Oil resistance, resulting in poor fuel supply, the engine appears to start difficult, slow acceleration and other symptoms, will automatically turn off the fire. When the tubing due to aging, deformation and impurity blockage to reduce the oil cross-sectional area, or because the oil and dirt plug into the oil filter and diesel filter, will cause the fuel shortage and make the engine power down and start difficult. The inspection and removal of this failure can be done in the car. Pump oil to a certain pressure, release the bleed screw, if the bubble overflow and always exhaust, then the oil into the air; if there is no bubbles but the fuel from the deflated screw overflow, then the oil is Clogged. The normal phenomenon is a slight release of the bleed screw, immediately the oil column to a certain pressure jet out. Troubleshooting is to find damaged or aging washers, joints or tubing to be replaced; to prevent such failure is the way to clean the oil filter and diesel filter, check the pipeline, found a problem in a timely manner to solve.

(2) oil pump piston spring break

The engine suddenly turns off during operation and can not start. Loosen the air screw to check the fuel injection pump low pressure oil chamber without fuel or little, hand pump pump oil to the entire low pressure oil chamber full of oil, clean the air to restart, the engine back to normal, but driving a distance again after the automatic flameout. This failure phenomenon is likely to be Baotou North North heavy truck accessories piston pump spring break. This fault can be removed on the car, remove the screw, replace the spring can be.

(3) oil pump check valve seal is not strict

After the start of the engine work properly, but the flame out of parking after a certain period of time there is difficult to start, loosen the bleed screw bubble overflow, need to re-discharge the air before starting. This failure is mostly caused by the oil pump check valve seal is not strict. Check the method is to unscrew the oil pump out of the oil pump, pump the fuel pump to make oil full of oil joint oil chamber, such as the mouth of the oil quickly fell, then the check valve seal is not good. Remove the check valve to check the seal and is intact, check valve spring is broken or deformation, seal seat surface is attached with particulate impurities, according to the specific circumstances were taken grinding sealing surface, replace the check valve or check valve spring will be fault exclude. The normal situation is the oil surface in 3 minutes or more does not appear to fall, pump hands oil pump oil from the oil out of a strong joint.

(4) high pressure tubing blocked

When a cylinder high-pressure tubing due to deformation or impurities and clogging occurs, start the engine in the tubing parts may have a significant percussion, and because the cylinder can not work properly and the engine power drop. Check the method is to squeeze the high-pressure tubing into the oil at the end of the nut, when the loosening of a cylinder after the percussion disappeared, can be concluded that the cylinder for the failure of the tank, replace the Baotou North heavy truck accessories tubing failure can be ruled out.

(5) fuel injector couple stuck

When the injector needle is stuck in the closed position, there is a regular percussion near the cylinder head. It is due to the fuel injection pump when the pressure wave caused by the impact of the injector. Judgment method is to loosen the high-pressure tubing at the end of the injector, such as the percussion sound disappears, can be concluded that the cylinder injector needle stuck.