Fuel pump diesel engine is the "heart", and its role is to establish high-pressure diesel, and the work order and in accordance with the engine load variation, time, and quantity to be supplied to the diesel fuel pump, injected into the combustion chamber. Once an internal fuel pump leak, and even high-pressure and low Enveloper Oil Oil-linked, will start a diesel engine difficulties, unable to work, unable to operate normally. At the same time leaked diesel oil into the lubricants, so that lubricants diluted. Metamorphism, leading to an increased mechanical wear.
A leaking fuel pump, the diagnostic methods
Fuel pump leak occurred within the generally difficult to detect with the naked eye. If the engines start difficulties, power down, a row Oil endless air, and sometimes off automatically, or at the same time Shell Oil injection pump oil at the end of planar unusual increase in fuel pump can be diagnosed as internal leakage.
2 fuel pump leak in the main part
⑴ plunger sets installed at the shoulder-leak
The plunger-type fuel pump plunger sets of the large circular cylindrical pump shoulder and upper body located between the sealing gaskets, rely on the combination of the two to achieve the precision machining sealed. This is a ring, a small area enclosed plane. So the obvious traces of Squeeze, will cause a large number of diesel leaked, the diesel engine does not work, and sometimes there will be at low speed can be barely operational, and the increase in speed will be inhaling air phenomenon.
Taiwan plunger sets installed at the shoulder of a squeeze is the main reason for signs of tightening oil from the valve seat to bear too much torque, and high-pressure diesel changes in the volatility of the stress here will be accelerated fatigue damage.
⑵ leak between the plunger and plunger
Plunger and plunger sets of the original with very sophisticated and space only 0.002 ~ 0.003 mm, both matching and after grinding, especially high precision surface roughness. In use, if diesel contains impurities and moisture, caused plunger-and wear or corrosion, increased space, diesel leak occurred, thus unable to build high-pressure diesel.
⑶ plunger positioning screw sets the oil spill
Under the plunger sets with a set screw 1 mm thick copper gaskets, seals from its main role. If this small leak with washers, or raising it, the breakdown of Inner plunger diesel did the set screw to the leak.
⑷ filling valve leakage
When filling valve with a tight oil seat at the end between the copper (or nylon) sealing gaskets. Rupture, deformation, or filling valve at the end of tightening tight, filling the top of the high-pressure valve cavity oil will be below the low-pressure phase is communication, which can not produce high-pressure diesel injection pump.
⑸ oil return valve leakage
Multi-cylinder fuel pump valve settings back to the purpose of the oil is to give upper level of injection pump, diesel oil to around 100 kPa pressure. If oil return valve and the valve seat wear, rust Tong, valves culvert Dianqi, or to the oil and to the plunger sets into the mouth of diesel oil pressure dropped, or inhalation of air injection pump, resulting inability to work or even diesel automatic flameout.
⑹ pump putter and hub of oil spills
When the plunger pump with the putter had very bushings wear, or putting on the ring damage, and the leaked fuel will increase significantly. If the vent hole plug, which will be part of diesel fuel pump oil into the tank.
3 prevent leaking fuel pump of the technical measures
⑴ strengthen the fuel supply system maintenance, the use of sedimentation and filtration, after full diesel fuel tank regularly released, sedimentation Cup and thickness and filter impurities in the water, and cleaning them, so as to reduce the wear-and precision.
⑵ correct fuel pump assembly. Assembly, the parts must be thoroughly cleaned, to prevent impurities in the adhesion with the surface parts. Dismounting plunger pack filling valve counterpart, it is necessary to remove the pair, installation and replacement. Plunger should not arbitrarily selected and, if necessary, do a good job marking, so as to avoid confusion, resulting in a dual meet plunger gap too large oil spills. Do not pay attention to the loss and leakage loaded plunger positioning screw sets the copper washers. Technical manuals in accordance with the provisions of torque (60 N.m ~ 70N.m) Tightening the tight oil valve seat. Not a hard twist, it is non-standard installation governor caused. Return OUR request author personally inspect the installation from start to finish again. After listening to the users and analysis, I am skeptical. I personally governor is installed, the installation size and flexibility are good. However, it will not able to say specific reasons. Open governor inspection, all normal, pulling teeth-examination, felt that they were two-cylinder plunger sensitivity there Lag card phenomenon, but it is not very obvious. Removing a plunger, piston kit found deformed copper pads, as if shallow plate-shaped, with the body-checked and found that a little depression. Cause is the cause of the malfunction: users found that the pipeline after the oil spill in the pipeline forced pull tight to prevent the nut before the event, and pull force to bear on tight oil valve, the pressure over copper pads affordability deformed with a plunger sets of deformation, Plunger activities that obstructed the sky above fault.
Approach: ① inspection cylinder plunger which is a failure, a release valve tight oil blocks, with hammer blow to adjust gear to restore vertical plunger, then slowly and gradually pull tight, the pull of the tight control in allowing dirt range.
Approach: ②gasket with a pair of scissors Qiaoqi part re-installation, the pull of the tight control in a certain range, the machine testing, fault solved.