What causes excessive fuel supply to diesel generator set fuel injection pump?

1. The oil supply of the fuel injection pump plunger is adjusted too large, or the locking screw of the adjusting gear ring is loosened and the adjusting ring gear is displaced, resulting in the excessive oil supply of the fuel injection pump.

2. The adjustment screw that limits the maximum oil volume of the rack in the governor is too large or the throttle handle limiting screw is adjusted too much.

3. Too much oil in the governor will increase the oil supply and lead to "flying cars".

1) There is air in the fuel injection pump or the oil pipe joint is loose and leaking.

2) The oil inlet pressure is too low, such as insufficient oil supply in the oil conveying system, too weak the spring of the oil return valve in the fuel injection group, and the blockage of the diesel filter.

3) The oil supply amount adjusted by the column cold is too small (that is, the relative position of the adjusting gear ring and the rack is not right), or the ballast screw of the adjusting gear ring is loose and displaced, so that the oil supply is too small.

4) Excessive wear of the plunger couple.

5) The oil outlet valve is not tightly sealed, which is mainly caused by excessive wear of the oil outlet valve, impurities entering the oil pump and weakening of the spring elasticity of the oil outlet valve.

6) The adjustment screw adjustment that limits the maximum oil volume of the rack in the governor is too small or the adjustment of the throttle handle limiting screw is too small.

The reason why the EFI diesel engine is difficult to start and the oil return is large.

Dear, I'm glad to answer for you! The reasons for the difficulty of starting the EFI diesel engine and the large amount of oil return are as follows:1

Loss of pressure in high-pressure oil circuit: EFI diesel engines need enough high-pressure oil to complete fuel injection. Leaks or other problems in the high-pressure oil circuit can lead to difficult start-up and high oil returns.

2.Clogged fuel filter: The fuel filter is used to filter the fuel entering the injector, and if the fuel filter is clogged, it will affect the fuel flow weight and injection efficiency, resulting in difficult start-up and high oil return.

3.Injector failure: Injectors are one of the key components in EFI diesel engines, they inject fuel into the cylinder to complete the combustion process.

If the injector is damaged or fails, it will lead to difficulty in starting and large oil return. Dry Pure 4Engine Wukai sensor failure:

EFI diesel engines need to monitor the operating status of the engine through various sensors and adjust the amount of fuel injected according to them. If the sensor fails, it will be difficult to start and the oil return will be large.

The detection and adjustment method of fuel supply time of diesel generator set fuel injection pump is as follows:

Step 1: Install the diesel generator set fuel injection pump on the test bench, seal the oil return port, connect the oil inlet pipe, fix the oil supply tooth rod on the oil supply position, loosen the air release screw on the oil pump, start the test bench, exhaust the air, and tighten the air release screw.

Step 2: Adjust the oil supply pressure of the test bench to.

Step 3: Adjust the height of the measuring cylinder and connect the high-pressure oil pipe of the standard injector.

Step 4: Put the control arm on the governor in the oil stop position, loosen the air release screw on the standard injector, and start the test bench, at this time, the oil return pipe of the standard fuel injector should have a large amount of oil return.

Step 5: Place the upper control arm of the governor in the full load position, and at the same time make the plunger of the first cylinder in the bottom dead center position, use a special wrench to rotate the dial slowly and evenly according to the working rotation direction of the oil pump, and pay attention to the fuel flow from the interface of the return pipe of the standard injector. When the oil at the return nozzle has just stopped flowing out (at this time, the plunger just closes the oil inlet hole), it is the starting point of the oil supply of the first cylinder, and the oil supply advance angle can be read from the dial.

If it does not meet the requirements, it can be adjusted by rotating the adjusting screw on the tappet or increasing or decreasing the thickness of the gasket.

Step 6: Take the starting point of the first cylinder oil supply as the benchmark, check and adjust the angle of the oil supply interval of each cylinder according to the above method according to the number of cylinders of the engine and the working sequence of the fuel injection pump. The requirement is that the angular deviation of the oil supply interval between the adjacent two cylinders is not greater than .

Fuel injection pump supply time (term: fuel timing) is a very important parameter for whether the diesel engine is working properly or not. To solve the problem of "incorrect fuel supply time of the fuel injection pump."

Diesel generator sets.

The best way to "run a malfunction" is to readjust its "fuel timing" as required by the instructions.

In the long-term work, due to the combined action of the high-pressure oil, the grinding of mechanical impurities and the sitting of the pressure spring, the matching surface of the needle valve and the valve body will be worn, which will cause the leakage before the injection and the dripping of oil after the oil is broken, resulting in poor atomization, incomplete combustion, a sharp increase in carbon smoke and serious carbon deposits. Therefore, regular maintenance must be carried out on the injector.

1) When disassembling, remember the cylinder sequence of each injector.

The injectors are removed from under the cylinder head, subjected to a simple external cleaning, and then disassembled, inspected, and assembled one by one to prevent the same parts of different injectors from mixing with each other during assembly. The specific steps are: first clamp the nozzle hole of the fuel injector down on the vice, remove the pressure screw cap, pressure regulating screw and spring and clean it.

Then fix the injector turn around on the vice, loosen the coupling parts to fasten the screw sleeve, remove the injector coupling parts, and carry out the following inspection after necessary cleaning.

2) The inspection is divided into visual inspection and sliding test.

The mating surface of the needle valve and the valve body shall not be burned or corroded; The shaft needle of the needle valve must not be deformed or otherwise damaged. When doing the sliding test, the valve body must be tilted about 60 degrees, and the needle valve should be pulled out of about 1 3 strokes and then released, and the needle valve should be able to slide smoothly by its own weight; Turn the needle valve position, repeat the above operation, if the needle valve does not slide smoothly in any position, the needle valve coupling should be replaced.

3) Assemble. Clean the body and its oil passage, and assemble the pressure regulating spring and pressure regulating screw parts together. Note that the pressure regulating screw should not be tightened too tightly, so that it is easy to vent and clean the whole during the performance check at a later stage. Place the usable or replaced needle valve parts in a plastic basin filled with clean diesel fuel and swim the needle valve back and forth for thorough cleaning.

The pressure regulating part of the injector (should be below) is fixed on the vice, the needle valve part is buckled on the joint surface according to the positioning requirements, and then the coupling part is tightened and the screw sleeve is tightened, and then the following performance check is carried out.

1. The oil supply of the fuel injection pump plunger is adjusted too large, or the locking screw of the adjusting gear ring is loosened and the adjusting ring gear is displaced, resulting in the excessive oil supply of the fuel injection pump.

2. The adjustment screw that limits the maximum oil volume of the rack in the governor is too large or the throttle handle limiting screw is adjusted too much.

3. Too much oil in the governor will increase the oil supply and lead to "flying cars".

When the amount of oil supply is too much, the fuel consumption will increase, the fuel combustion is incomplete, the diesel generator exhaust emits black smoke, the combustion chamber is seriously depositioned, the wear of the cylinder, piston and piston ring is accelerated, and even the Yuchai diesel generator set is overheated and knocked on the cylinder.