Analysis of the Reasons for Insufficient Power Output of F6L913 Diesel Engine

The air filter is clogged

The clogging of the air filter increases the intake resistance and reduces the amount of air entering the cylinder, resulting in incomplete diesel combustion and insufficient engine power.

Troubleshooting: Regardless of whether the air filter is wet or dry, the air filter element should be frequently cleaned or the dust on the paper filter element should be removed. If necessary, the filter element should be replaced to ensure the cleanliness of the air filter.

2. Fault of the exhaust gas turbocharger

Blockage or leakage of the intake pipes of the compressor and turbine of the exhaust gas turbocharger, as well as damage to the bearings, can all lead to a reduction in the amount of air entering the cylinder, resulting in incomplete combustion of diesel and a decrease in the power of the diesel engine.

Troubleshooting: When the turbocharger experiences the above situations, the intake pipe and the casing should be cleaned respectively, the dirt on the surface of the impeller should be wiped clean, the nuts and clamps on the mating surface should be tightened, and the bearings should be inspected or replaced, etc.

3. The exhaust pipe or muffler is blocked

Blockage of the exhaust pipe or muffler can cause poor exhaust, increased exhaust resistance, decreased charging efficiency, and result in poor power output of the diesel engine.

Troubleshooting: Regularly check the carbon deposits in the exhaust pipe and muffler. If there is too much carbon deposit, mechanical unblocking or chemical cleaning methods can be adopted to clean it, ensuring that the exhaust from the exhaust pipe and muffler is unobstructed

4. Inaccurate fuel supply advance Angle and diesel supply failure

1) The fuel supply advance Angle is inaccurate. If the fuel injection advance Angle is too large or too small, it will cause the fuel injection time to be too early or too late, resulting in incomplete combustion of diesel and a decrease in the output power of the fuel engine.

Troubleshooting: Loosen the coupling fastening screws on the transmission shaft of the high-pressure pump, readjust the oil supply advance Angle as required, and then tighten the screws.

2) The diesel filter is clogged, which increases the flow resistance of diesel, reduces the amount of oil entering the high-pressure pump, and accordingly decreases the amount of diesel injected into the cylinder, resulting in insufficient output dynamic force of the diesel engine.

Troubleshooting: Regularly inspect and clean the diesel filter element, and replace it if necessary to ensure the cleanliness of the diesel filter.

3) The low-pressure oil passage is blocked or the diesel pipeline is bent, causing the oil passage to be unobstructed and increasing the resistance to diesel flow.

Troubleshooting: Inspect and reinstall the low-pressure diesel pipeline, and replace it if necessary to ensure the smooth flow of the diesel pipeline.

4) There is air in the fuel line, causing excessive fluctuations in the fuel injection pressure.

Troubleshooting: Use the oil transfer pump to remove the air in the low-pressure oil circuit, eliminate the problem of non-sealing, and tighten the oil pipe joint.

5) Damage, seizing or poor atomization of the fuel injector pairs can cause individual cylinders to fail to work and result in insufficient engine power.

Troubleshooting: Clean, grind or replace the new fuel injector pair, calibrate the fuel injector, check and adjust the fuel injection pressure and atomization quality of the fuel injector.

6) Insufficient oil supply or uneven oil supply from the high-pressure pump.

Troubleshooting: Inspect, repair or replace the mating parts on the high-pressure pump test bench, and re-adjust the fuel supply performance parameters of the fuel injection pump.

7) The maximum oil supply limit screw is improperly adjusted, or the control arm of the high-pressure pump cannot rotate to the maximum oil supply position.

Troubleshooting: Adjust the high-speed limit screw or the control arm of the high-pressure pump.

8) The high-speed adjusting nut of the adjuster is screwed in too much.

Troubleshooting: Inspect and adjust the speed regulator on the high-pressure pump test bench.

9) Insufficient fuel supply from the oil pump leads to a reduction in the amount of diesel injected into the cylinder.

Troubleshooting: Inspect or replace the plunger of the oil transfer pump.

5. Wear of piston rings, pistons and cylinder liners

Severe wear of the piston rings, rubber adhesion and jamming, or misalignment of the piston rings, excessive wear of the piston and cylinder liner, or severe scratches on the piston and cylinder liner can all lead to the failure of cylinder sealing, resulting in weak compression and a decrease in the output power of the diesel engine.

Troubleshooting: Replace the cylinder liner, piston and piston rings.

6. Cylinder head failure

1) Poor sealing of the intake and exhaust valves leads to air leakage during compression, reduced compression effect, difficulty in ignition, incomplete combustion of diesel, and a decrease in diesel engine power.

Troubleshooting: Reaming and grinding the mating surfaces of the valve and the valve seat ring to enhance their sealing performance. Replace the valve and the valve seat ring if necessary.

2) Inaccurate valve clearance leads to air leakage, resulting in a decline in cylinder compression effect, deterioration of combustion conditions, difficulty in ignition, and a decrease in diesel engine power output.

Troubleshooting: Adjust the valve clearance to reach the specified value.

3) The valve spring is damaged, causing difficulties in valve return, valve leakage, reduced cylinder compression effect, and a decrease in diesel engine power output.

Troubleshooting: Replace the valve spring.

4) The cylinder gasket was damaged, causing air leakage at the joint surface between the cylinder head and the engine block. This allowed high-pressure air inside the cylinder block to enter the oil passage, resulting in poor lubrication conditions and black smoke emissions, which led to insufficient diesel power output.

Troubleshooting: Replace the cylinder gasket and tighten the cylinder head nut to the specified torque.

5) The copper gasket of the fuel injector installation hole was damaged, causing air leakage. The combustion conditions of some cylinders deteriorated, resulting in insufficient power output of the diesel engine.

Troubleshooting: Clean the carbon deposits and replace the copper gasket.

7. Cooling system failure

When the temperature of the diesel engine is too low, it is not conducive to the formation and combustion of the combustible mixture, resulting in a decrease in thermal efficiency and a reduction in the power of the diesel engine. At the same time, when the temperature of the diesel engine is too low, the viscosity of the engine oil increases, increasing the operating resistance and power loss.

Troubleshooting: Inspect the cooling system and ensure that the diesel engine operates at the normal working temperature (cooling water temperature 80-95℃).

2) When the diesel engine temperature is too high, the cylinder inflation volume decreases, the diesel combustion is incomplete, the power of the diesel engine drops, and fuel consumption increases.

Troubleshooting: Check the working conditions of the fan, fan clutch, air deflector and heat sink to ensure that the diesel engine operates at a normal temperature.

8. Lubrication system failure

1) If the viscosity of the engine oil is too high or viscosity enhancers are added randomly to the engine oil, the operating resistance of the diesel engine will increase and the power consumption will rise.

Troubleshooting: Clean the lubrication system and replace it with engine oil of the appropriate grade.

2) There is too much engine oil in the oil pan, and even the crankshaft is immersed in the oil, which increases the operating resistance and reduces the output power of the diesel engine.

Troubleshooting: Drain the excess engine oil.