Analysis of the Reasons for Insufficient Power of the 913 Series Diesel Engine

Abstract

The 913 series diesel engines of Deutz Company in Germany are widely used in various types of construction machinery. Insufficient power output is a common fault phenomenon. This article briefly analyzes the causes of this fault and proposes corresponding methods to eliminate it

1. Intake system failure

The clogging of the air filter increases the intake resistance and reduces the amount of air entering the cylinder, resulting in incomplete combustion of diesel 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. Replace the filter element if necessary to ensure the cleanliness of the air filter.

2. Fuel supply system failure

2.1 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 diesel engine.

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

2.2 Diesel filter blockage

The blockage of the diesel filter 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 power 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.

2.3 Blockage of the low-pressure oil circuit or bending of the diesel pipeline

Blockage of the low-pressure oil passage or sharp bending of the diesel pipeline can cause the oil passage to be blocked, 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.

2.4 There is air in the oil circuit

Air in the fuel line causes excessive fluctuations in the fuel injection pressure.

Troubleshooting: Use the hand oil pump in the oil transfer pump to remove the air in the low-pressure oil circuit; eliminate the non-sealing phenomenon, such as tightening the oil pipe joint.

2.5 Damage, seizing or poor atomization of the fuel injector pair

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

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

2.6 Insufficient oil supply or uneven oil supply from the high-pressure pump

When the high-pressure pump fails to supply fuel or the fuel supply is uneven, it will cause inconsistencies in the quantity, composition and quality of the combustible mixture in each cylinder, thereby resulting in insufficient power of the diesel engine.

Troubleshooting: Inspect and repair the high-pressure pump, and readjust the fuel supply performance parameters of the fuel injection pump on the high-pressure pump test bench.

2.7 Improper adjustment of the maximum fuel supply limit screw or failure of the high-pressure pump control arm to reach the maximum fuel supply position will result in insufficient circulating fuel supply when the diesel engine load increases, thereby reducing the diesel engine's power.

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

2.8 Insufficient fuel supply from the fuel transfer 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, and replace the belt of the oil transfer pump.

Wear of the 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.

4. Cylinder head failure

4.1 The intake and exhaust valves are not tightly sealed

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, and replacing the valve and the valve seat ring if necessary.

4.2 Inaccurate valve clearance

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.

4.3 The elastic force of the valve spring decreases or is damaged

The decline or damage of the elastic force of the valve spring makes it difficult for the valves to return to their original positions, causing valve leakage and a reduction in the compression effect of the cylinder, which leads to a decrease in the power output of the diesel engine.

Troubleshooting: Replace the valve spring.

4.4 The cylinder gasket is damaged

The damage of the cylinder gasket causes air leakage at the joint surface between the cylinder head and the engine block, allowing high-pressure air inside the cylinder block to enter the oil passage, resulting in poor lubrication conditions and black smoke emissions, and insufficient power output of the diesel engine.

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

4.5 The copper gasket of the fuel injector installation hole is damaged

When the copper gasket of the fuel injector installation hole is damaged, it causes air leakage. The combustion conditions of some cylinders deteriorate, resulting in insufficient power output of the diesel engine.

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

5. 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. This not only causes smoke in the exhaust but also reduces the power of the diesel engine.

Troubleshooting: Clean the intake pipe and casing of the turbocharger respectively, wipe off the dirt on the surface of the impeller, tighten the nuts and clamps on the mating surface, and inspect or replace the bearings, etc.

The exhaust pipe or muffler is blocked

Blockage of the exhaust pipe or muffler can lead to poor exhaust, increased exhaust resistance, decreased charging efficiency, and insufficient power output of the diesel engine.

Troubleshooting: Check the carbon deposits in the exhaust pipe and muffler. If there are too many carbon deposits, mechanical or chemical methods can be used to clean them to ensure smooth exhaust from the exhaust pipe and muffler.

7. Cooling system failure

7.1 The diesel engine temperature is too low

When the temperature of a diesel engine is too low, it is not conducive to the formation and combustion of the combustible mixture, resulting in reduced thermal efficiency and decreased power of the diesel engine. At the same time, if the temperature of the diesel engine is too low, the viscosity of the engine oil will increase, which will increase the operating resistance and power loss.

Troubleshooting: Check the working performance of each component of the cooling system and the amount of cooling water, and keep the diesel engine running at the normal operating temperature (cooling water temperature 80-95℃).

7.2 The diesel engine temperature is too high

Excessively high temperatures in diesel engines reduce the cylinder inflation volume, resulting in incomplete combustion of diesel, a decrease in diesel engine power, and an increase in fuel consumption.

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

If the viscosity of the engine oil is too high or it is too dirty, 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.

Engineering Construction Machinery 2005.NO.8